Saturday, 31 December 2011

The One-Dimensional Hydrogen Atom: Quantum Solutions

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By a ‘one-dimensional hydrogen atom’ has to be understood an electron and a proton locked together into a one-dimensional box. Depending on the distance r of the electron to the proton and due to Coulombic attraction the electron possesses potential energy Ep(r) = - e2/(4π ε0 r) with e the charge of the electron (proton) and ε0 the vacuum permittivity.

What follows is a ‘semi-heuristic’ derivation of the wave functions, electron densities and energy quantisation of such a quantum system.

The wave functions of a quantum system are solutions to the time-independent form of the Schrödinger Equation:

Hψ = Eψ

With ψ the amplitude of the wave function, H the Hamiltonian Operator and E the total energy of the quantum system (E = Ek + Ep).

For the one dimensional hydrogen atom the Schrödinger Equation becomes:

- δψ”(r) - ρψ/r = Eψ
With:

• r the distance between the electron and the proton (assume the latter to be completely stationary)

• ψ (i.e. ψ(r)) the amplitude of the wave function as a function of r

• - ρ ψ/r the potential energy term resulting from the coulombic attraction between the electron and the proton

• δ and ρ two material constants that can be found in any decent physics book. Both are positive.

• E the total energy which in this case is always negative (E < 0), reaching 0 only for the unbound electron (r = ∞)

Dividing everything by - δ and then multiplying by r gives: rψ” + (ρ/δ) ψ = - (E/δ)ψr or rψ” = [-(E/δ)r - (ρ/δ)]ψ

Substituting: ψ = y, r = x the differential equation (DE) becomes: xy”= (α2x - β)y

with α2 = - (E/δ)
and β = ρ/δ

We know the system is quantised and a colleague (‘Watson.fawkes’) at the ScienceMadness.org forum proposed β = 2 α for the ground state.

Let’s look at this proposed ground state energy:

α = β/2

Square both sides:

α2 = β2/4

which works out as E1 = - ρ3/(4 δ2), the ground state energy of the electron, which is indeed ≠ 0 and negative as it should be.

The DE can then be re-written as xy”= (α2x - 2α)y

The proposed solution to this DE is y = xe-αx and it does indeed fit the equation xy”= (α2 - 2α)y. Plugging y = xe-αx into the DE shows it is a solution for it.

Let’s now look at the first excitation:

It was proposed that for the first excitation α = β/4, so E2 = - ρ3/(16 δ2)

The factors 4 and 16 would suggest quantisation as (2n)2 with n the quantum number, so that:

En = - ρ3/((2n)2 δ2) = E1/n2

The DE for n = 2 would then be:

xy”= (α2x - 4α)y

Well, assuming the energy quantisation is indeed En = - ¼ (ρ32)(1/n)2, then it can be shown easily with α2 = - (E/δ) that α = ½ (ρ/δ)3/2(1/n)

Plugging y = x(1- αx)e-αx into the DE shows that it is a solution for β = 4α and presumably other solutions exist for β = 6α, β = 8α etc.

So that a function:

yn = f(x,n)e^(- ½(ρ/δ)3/2(1/n)x)

would appear a likely general solution, with f(x,n) a suitable polynomial.

Regarding the quantisation:

En = - ρ3/((2n)2 δ2)

And from above α2 = - (E/δ), E = - α2δ

Thus: αn = ½ (ρ/δ)3/2 (1/n)

Set α1 = ½ (ρ/δ)3/2

Then α2 = α1/2

α3 = α1/3

...

αn = α1/n

So y2 = x(1 - ½ α1x )e^(- ½ α1x)

And the second excitation was found to be:

y3 = x(1 - 2αx + 2/3.α2x2)e-αx

With β = 6α and α = α1/3

A General solution?

Assume that: yn = x F(x, n, αn)e^(-αnx)

With F = 1 + c1x + c2x2 + … + cn-1xn-1

Or F = [1+ (i from 1 to n-1) ∑ cixi]

Setting up the polynomial using F = 1 + ∑cixi (from i = 1 to n - 1) was surprisingly easy. First y was transformed to y = Ge-αx with G = x + ∑cixi+1.

y” can now be written as e-αx [G” - 2αG’ + α2G]

The x and the factor e-αx in the equation:

xy” = (α2x - 2nα)xFe-αx

then drop out and the equation becomes:

G” - 2αG’ + α2G = (α2x - 2nα)F

After deriving G twice and a bit of rearranging, the full polynomial is then obtained. All its coefficients need to be zero to satisfy the DE. The recursing is really easy because it turns out that ci is always a simple function of ci-1:

ci = 2/(i(i+1)) . α (i-n) ci-1 and c0 = 1

For i=1, c1 = α(1-n) which fits for n=1 (c1 = 0) and n=2 (c1 = -α) and for n=3 (c1 = -2α), all as found above.

For i=2, c2 = 1/3 α2(2-n)(1-n)

Which for n=3 gives c2 = 2/3 α2, as found above.

c3 = 1/18 . α3(3-n)(2-n)(1-n)

Etc, etc for each ci.

Note also that in all cases α = α1/n

The general formula for ci appears to be:

ci = 2i / i!(i+1)!) α Π ((i-n)(i-1-n)(i-2-n)…(2-n)(1-n))

with Π from i to 1 and α = α1/n

The coefficients ci alternate in sign (+ or -) in such a way that the polynomial x.F always has n real roots (zero points),

Plugging ci into F = 1 + ∑cixi then yields the general solution for the wave functions:

yn = x Fe^(-αnx)

This leaves in essence only one pesky little problem, that of the normalisation of the wave functions. The Schrödinger Equation is a second order DE and so far only one integration constant has been deployed, i.e. the quantum number n.

But there is a second ‘boundary condition’ that has to be imposed on the system. In quantum physics it is well understood that the probability of finding the electron at position r, P(r), is given by:

P(r) = ψ2(r)

We also know that the total probability of finding the particle between r=0 and r=∞ must be 1, so that:

(from 0 to ∞)∫ ψ2(r) dr = 1, known as the ‘normalisation condition’.

To satisfy it we multiply the non-normalised wave function ψ with a normalisation constant A, so that ψnorm = Aψ and thus with some rearranging:

A2 = 1 / [(from 0 to ∞)∫ψ2(r)dr]

Needless to say, given the complexity of ∫ψ2(r)dr, this is no walk in the park and I didn’t attempt to find a general expression for An . Instead I numerically integrated ψ2dr for n = 1, 2 and 3 (for ψ1 the normalisation constant is in fact easily calculated as A1 = 2α13/2).

Below are the normalised wave functions and electron probability distributions for the ground state and the first two excitations of a one-dimensional hydrogen atom:

Monday, 31 October 2011

Cobalt Carbonate - CoCO3 - 200 g

Chemical formula: CoCO3

Synonyms: cobalt carbonate, cobaltous carbonate

Amount: 200 g

Appearance and odour: fine pink-purple powder without appreciable odour

Packaging: professional wide necked, white HDPE bottle with blue conical seal cap and tamper ring. Labelled. Bottle and cap are UN approved and reusable.

Description and uses: cobalt carbonate finds uses as a pottery glaze pigment (cobalt blue).

For chemists this is a precursor to most other cobalt salts, as it dissolves readily and completely in most acids, with liberation of carbon dioxide.

On strong heating it loses both carbon dioxide, leaving behind black cobalt (II) oxide (CoO).

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CAS: 513-79-1

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Copper Basic Carbonate - Cu2(OH)2CO3 - 200 g

Chemical formula: Cu2(OH)2CO3 (Cu(OH)2.CuCO3)

Synonyms: copper carbonate, copper hydroxy carbonate, cupric hydroxy carbonate, copper (II) hydroxy carbonate, Malachite (mineral), verdigris pigment

Amount: 200 g

Appearance and odour: fine green-grey powder without appreciable odour

Packaging: professional wide necked, white HDPE bottle with blue conical seal cap and tamper ring. Labelled. Bottle and cap are UN approved and reusable.

Description and uses: copper basic carbonate finds uses as a pottery glaze pigment (green) and as a fungicide.

It contains 70 w% copper (as CuO).

For chemists this is a precursor to most other copper salts, as it dissolves readily and completely in most acids, with liberation of carbon dioxide.

On strong heating it loses both carbon dioxide and water, leaving behind black CuO.

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CAS: 12069-69-1

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Sunday, 30 October 2011

Buffer Combo Master Solutions - pH 4.7 and 7.5

Chemical compositions: an acetate/acetic acid mixture and a proprietary solution of TRIS/HCl

Amount: 2 x 100 ml of concentrate, each makes 500 actual buffer solution, one of pH 4.7, the other of pH 7.5

Appearance and odour: pH 4.7: clear liquid, odour reminiscent of vinegar, pH 7.5: clear liquid, without appreciable odour

Packaging: professional wide necked, white HDPE bottles with blue conical seal cap and tamper ring. Labelled. Bottles and caps are UN approved and reusable.

Description and uses:
Dilute 100 ml (content of the bottle you receive) to approx. 500 ml final volume, with deionised or very soft mineral water to obtain a buffer solution of pH 4.7, the other of pH 7.5, both with excellent buffering capacity.

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Buffer Master Solution - pH 7.5 - TRIS/HCl buffer

Chemical composition: proprietary mixed solution of TRIS/HCl

Amount: 100 ml of concentrate, makes 500 ml actual buffer

Appearance and odour: clear liquid, without appreciable odour

Packaging: professional wide necked, white HDPE bottle with blue conical seal cap and tamper ring. Labelled. Bottle and cap are UN approved and reusable.

Description and uses:
This is a master solution of TRIS/HCl buffer which on dilution yields a buffer solution of pH = 7.5.

Dilute 100 ml (content of the bottle you receive) to approx. 500 ml, with deionised or very soft mineral water to obtain a buffer solution with high buffering capacity.

Customers may also be interested in our
pH = 4.7 Master buffer solution.

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Sunday, 16 October 2011

Titanium Dioxide - TiO2 - Food Grade - > 99 %

Chemical formula: TiO2

Synonyms: titanium (IV) oxide, titania, Anatase

Amount: 200 g (note that larger quantities can be made available on request)

Appearance and odour: white, fine powder without appreciable odour.

Packaging: professional wide necked, white HDPE bottle with blue conical seal cap and tamper ring. Labelled. Bottle and cap are UN approved and reusable.

Description and uses: titanium dioxide is titanium’s most widely used compound. It’s now by far the most important stable and non-toxic pure white pigment in use, finding high volume applications in paint, paper, plastics, rubber, paper, food and many other industry sectors. This grade on sale is a Food Grade product.

From a chemist’s perspective it’s a gateway compound to most other titanium compounds and even to the elemental metal itself (see below).

Commercial titanium dioxide is highly insoluble in water and most acids and only dissolves in acids like hydrofluoric (HF) or concentrated sulphuric acid (H2SO4). In the latter it dissolves quite well near boiling point, given some patience. Dissolution is quicker in molten sodium bisulphate or in mixtures of concentrated sulphuric acid and ammonium sulphate because in both cases higher temperatures can be reached (compared to concentrated sulphuric acid). It dissolves in all these solvents forming titanyl sulphate (TiOSO4). Strong dilution of these solutions causes this salt to hydrolyse and titanium (IV) hydroxide (Ti(OH)4) to precipitate. Freshly precipitated Ti(OH)4 is remarkably soluble in weaker acids (like HCl) but ages quickly, reverting back to the much less soluble oxide from.

Solutions of TiOSO4 can be reduced to Ti3+ (+III) bearing solutions by reduction with aluminium or zinc. The Ti3+ ion is coloured a wonderful deep blue, as only D-block ions can show. It’s very susceptible to oxidation by air oxygen, which oxidises it back to Ti (+IV). With hydrogen peroxide, Ti (+III) is first oxidised to Ti (+IV), then a Ti (+IV) peroxo complex forms. This complex has a deep orange-red colour and can be used for both qualitative (visual) and quantitative (photometry) analysis of titanium bearing materials.

Commercial titanium metal is produced by reduction of TiCl4 with magnesium metal in the so-called Kroll Process. But lower grade titanium metal can also be produced by means of heat boosted aluminothermic reduction of TiO2 with aluminium powder.

The basic reaction 3 TiO2 + 4 Al === > 3 Ti + 2 Al2O3 however doesn’t yield enough reaction heat to obtain the reaction products in the molten state and obtain good separation between the metal and the slag (alumina by-product). To overcome this, a so-called heat booster system is added to the mix. The booster comprises of extra aluminium and a stoichiometric amount of an oxidiser like potassium chlorate, sodium nitrate or even calcium sulphate. Both the basic reduction reaction and the booster reaction then run simultaneously, generating the heat required to allow liquid Ti metal to form. Search Google for ‘backyard titanium metal’ and click on the #1 listed web page for more information or contact me.

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CAS: 13463-67-7

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Wednesday, 12 October 2011

Buffer Master Solution - pH 4.7 - Acetate buffer

Chemical composition: equimolar sodium acetate - acetic acid solution

Amount: 100 ml of concentrate, makes 500 or 1,000 ml actual buffer solution

Appearance and odour: clear liquid, odour reminiscent of vinegar

Packaging: professional wide necked, white HDPE bottle with blue conical seal cap and tamper ring. Labelled. Bottle and cap are UN approved and reusable.

Description and uses:

This is a master solution of 1 M sodium acetate/acetic acid which on dilution yields a buffer solution of pH = 4.7.

Dilute 100 ml (content of the bottle you receive) to approx. 500 ml or 1000 ml final volume, with deionised or very soft mineral water. Lower dilution gives highest buffering capacity but final pH is always 4.7.

One of the most used and most stable buffering solutions available.

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Friday, 30 September 2011

Sodium Bicarbonate - 99.44 % - NaHCO3 - 200 g

Chemical formula: NaHCO3

Synonyms: sodium hydrogencarbonate, baking soda, bicar.

Amount: 200 g

Appearance and odour: white micro-crystalline powder, without appreciable odour

Packaging: professional wide necked, white HDPE bottle with blue conical seal cap and tamper ring. Labeled. Bottle and cap are UN approved and reusable.

Description and uses: sodium bicarbonate is the main constituent of baking soda but at this purity this isn't any old sodium bicarbonate (baling soda usually contains an anti-caking agent).

At about 200 centigrade or higher, sodium bicarbonate loses water and carbon dioxide very swiftly and is converted to pure anhydrous sodium carbonate (Na2CO3), a good primary alkaline standard for acid-base solutions and a premium dryinh gant for many organic solvents.

Sodium bicarbonate is only sparingly soluble in water and reacts slightly alkaline.

It has the peculiar property that the neutralisation reaction with weak acids, which releases carbon dioxide, is slightly endothermic, an interesting demonstration of an endothermic reaction.

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CAS: 144-55-8

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Calcium Carbonate - 99.9 % - CaCO3 - 200 g

Chemical formula: CaCO3

Synonyms: carbonate of calcium, chalk, limestone, calcite, marble.

Amount: 200 g

Appearance and odour: white powder without appreciable odour

Packaging: professional wide necked, white HDPE bottle with blue conical seal cap and tamper ring. Labelled. Bottle and cap are UN approved and reusable.

Description and uses: calcium carbonate is mostly found as limestone but at this purity this grade isn't any old piece of carbonaceous rock. This high grade is essentially free of alkali metal salts and produces a negative flame test for sodium.

An excellent source of other calcium salts, obtained by dissolving it in the according acid (carbon dioxide is the by-product).

Used analytically and quantitatively to fuse with minerals like Lepidolite to detect alkali metals like Lithium (Li), Rubidium (Rb) and Cesium (Cs). A highly pure calcium carbonate grade is necessary here to avoid sample contamination with alkali metal salts.

An interesting demonstration is that heated to very high temperature (over 1,000 celsius), calcium carbonate starts emitting light and losing carbon dioxide. The light was once referred to as 'lime light', a source of light now no longer in use. Prolonged heating at this temperature also causes the calcium carbonate to be completely converted to calcium oxide (CaO), aka 'quick lime'. The process of 'burning lime' was introduced to the British Isles by the Romans. Treated with water, quick lime absorbs water and is converted to calcium hydroxide (Ca(OH)2) aka 'slaked lime' in a process that can be violent and generates much heat. Slaked lime remains the basis for many mortars and cements since Roman times.

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CAS: 471-34-1

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Saturday, 24 September 2011

Zirconium Silicate - ZrSiO4 - Zircon - 200 g

Chemical formula: ZrSiO4

Synonyms: Zircon, zirconium (IV) orthosilicate, zirconium (+4) orthosilicate.

Amount: 200 g

Appearance and odour: fine, white powder without appreciable odour.

Description and uses: it is often used in pottery glazes as a colouring opacifier.

It is one of the main zirconium ores and thus a source of zirconium for chemists and industry. As this is a natural material it hasn’t been de-Hafnified and contains a few percent of hafnium silicate (HfSiO4). Hafnium and zirconium are chemically almost indistinguishable and thus very hard to separate.

Extracting the zirconium from this mineral is fairly easy and can be done with the following procedure, the so-called wet fusion process.

Weigh up a 20 % excess of NaOH with respect to the following stoichiometry: ZrSiO4 + 4 NaOH === > Na2ZrO3 + Na2SiO3

Dissolve the caustic soda carefully in the same amount of water (by weight), obtaining a 50 % NaOH solution. Mix all of this solution carefully with the zirconium silicate, obtaining a smooth paste. Heat this paste in a suitable crucible at 200 C for 2 h, then heat it for a further 2 h at 600 C.

After the heating cycle, allow to cool completely to room temperature and add enough water to cover the fusion product. Allow to soak overnight.

Carefully prize out the caustic fusion product, crush it and neutralise hydrolyse it carefully with an excess of strong hydrochloric acid (HCl). The zirconium will enter solution as zirconyl chloride (ZrOCl2), leaving behind fine, quite pure silica. Separate by decantation/filtration. The silica, washed and dried, is a valuable chemical in its own right.

The crude ZrOCl2 can be recrystallised by firstly concentrating the solution by partial solvent evaporation (boiling in), followed by adding concentrated HCl to the cooled concentrated ZrOCl2 solution which causes ZrOCl2.8H2O (zirconyl chloride octahydrate) to precipitate while most impurities (often iron) will remain in solution. This process can be repeated for extra purity if desired.

Highly pure zirconia (ZrO2) can be obtained from ZrOCl2 by hydrolysing it with NaOH, Na2CO3 or better strong ammonia solution. Freshly precipitated Zr(OH)4 is thus formed, which can be filtered off and used as a precursor for other zirconium salts or can be calcined to pure zirconia (ZrO2).

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CAS: 10101-52-7

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Manganese Carbonate - MnCO3 - 200 g

Chemical formula: MnCO3

Synonyms: manganese (II) carbonate, carbonate of manganese, manganous carbonate.

Amount: 200 g

Appearance and odour: fine, beige powder without appreciable odour.

Description and uses: often used in pottery glazes as a colouring agent/opacifier, it’s also one of the most versatile manganese (II) compounds and a stable and handy precursor to much of manganese’s complex chemistry. Water insoluble but readily soluble in acids, it is a gateway to many other manganese compounds.

Upon heating it starts losing carbon dioxide from about 200 C, in the presence of air yielding mixed oxides, mainly MnO2. In inert atmosphere (N2, Ar) or vacuum decomposition of the carbonate leaves behind MnO (manganese monoxide or manganese (II) oxide).

This technical grade MnCO3 dissolves completely in hot 1 M (1 mol/L) hydrochloric acid (HCl). The main contaminant is iron and it can be removed with little or no loss of product as follows.

Dissolve the amount you want purify in a precise amount of sulphuric acid but make sure there’s a little excess of MnCO3: this way the resulting (contaminated) manganese (II) sulphate will be almost neutral. Allow reaction until all fizzing stops and allow to clear. Don’t worry if it doesn’t clear completely. Decant or filter off, setting aside the excess MnCO3 for future use.

Take about one quarter of the solution and set the rest (the stock) aside. Add enough of an alkali (NaOH, KOH or ammonia solution are all good but not Na2CO3) to precipitate all the manganese and iron as hydroxides. Filter this and wash the filter cake of manganese and iron hydroxides with plentiful small aliquots of clean water until the filtrate is almost neutral. This washes out the soluble cations.

Now scoop out most of the precipitated hydroxides on the filter, add them to the stock solution and leave this to stand overnight (do not discard the filter, instead cover it with cling film to keep it moist). During standing overnight any contaminating iron will be converted to highly insoluble iron (III) oxide. Now filter the stock plus precipitates, using the same filter. The obtained solution is now essentially free of any iron and can be used to re-precipitate the manganese as purified MnCO3 or to crystallise it as quite pure MnSO4. This purification can also be carried out on manganese chloride: substitute sulphuric acid with hydrochloric acid.

Oxidation of manganous (II) salts in alkaline condition using hydrogen peroxide, hypochlorite or other results in manganese dioxide (MnO2) to precipitate.

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CAS: 598-62-9

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Tuesday, 13 September 2011

Sodium Dihydrogenphosphate - Na2H2PO4 - 150 g

Chemical formula: Na2H2PO4.2H2O

Synonyms: sodium dihydrogenphosphate.

Amount: 150 g

Appearance and odour: white crystalline powder, without appreciable odour

Packaging: professional wide necked, white HDPE bottle with blue conical seal cap and tamper ring. Labeled. Bottle and cap are UN approved and reusable.

Description and uses: sodium dihydrogenphosphate dihydrate is a water soluble orthophosphate compound and an excellent source of phosphate ions.

This salt is also a weak diprotic acid (H2PO4 -) and thus suitable to make rugged buffers. Neutralise it further with sodium hydroxide to obtain buffer solutions over a wide range of slightly acidic or even alkaline pHs.

By careful neutralisation with NH3, sodium ammonium hydrogenphosphate (NH4NaHPO4), aka 'cosmic salt', is obtained. Gentle heating transforms this into NaPO3, sodium metaphosphate.

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CAS: 108-95-2

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Thursday, 1 September 2011

Strontium Nitrate - Sr(NO3)2 - 99.4 % - 100 g

Chemical formula: Sr(NO3)2

Synonyms: nitrate of strontium.

Amount: 100 g

Appearance and odour: white crystalline powder, without appreciable odour

Packaging: professional wide necked, white HDPE bottle with blue conical seal cap and tamper ring. Labelled. Bottle and cap are UN approved and reusable.

Description and uses: a water soluble strontium compound. Used in a plethora of inorganic and organic synthesis. Confers a typical carmine red colour to a hot flame (bunsen or alcohol), due to spectral emission lines.

A powerful oxidiser on a par with potassium nitrate (saltpetre), used in fireworks to confer a red colour to the flame.

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CAS: 10042-76-9

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Tuesday, 30 August 2011

Cryolite - Sodium Hexafluoroaluminate - Na3AlF6 - 100 g

Chemical formula: Na3AlF6

Synonyms: Kryolite, trisodium hexafluoroaluminate, sodium aluminium fluoride

Amount: 100 g

Appearance and odour: fine white powder without appreciable odour.

Packaging: professional wide necked, white HDPE bottle with blue conical seal cap and tamper ring. Labelled. Bottle and cap are UN approved and reusable.

Description and uses: cryolite’s main usage industrially is in the production of aluminium by eletrolysis of a molten eutectic mixture of alumina and cryolite. Once mined, today it is mainly produced industrially.

Because of it chemical inertness and relatively low melting point (1,000 C) it is used also as a flux in pottery glazes.

Because of its eutectic forming properties with alumina, cryolite is also an excellent flux for aluminothermic reduction reactions (better known as ‘Thermite’ or ‘Goldschmidt’ reactions), greatly helping to fluidise the slag/metal mixture and thus promoting good separation of metal and slag. It performs better than the slightly less expensive fluorite (CaF2), the more traditional fluxing agent.

With hot, strong alkalis like NaOH, cryolite decomposes slowly to NaF and alumina.

Cryolite also has the curious property of having almost the exact same refractive index as water. A clear crystal of the material thus seemingly disappears when immersed in water, the subject of a neat party trick.

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CAS: 13775-53-6

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Friday, 26 August 2011

Tin Metal Powder - Sn - 63 micron - 100 g

Chemical formula: Sn

Synonyms: tin superfine powder

Amount: 100 g

Appearance and odour: heavy dark grey powder without any appreciable odour

Grade: 99.91 %, 63 micron, 230 Mesh

Packaging: professional wide necked, white HDPE bottle with blue conical seal cap and tamper ring. Labelled. Bottle and cap are UN approved and reusable.

Description and uses: superfine elemental tin powder.

Ideal for various organic and inorganic tin compound preparations.

With anhydrous HCl gas, anhydrous SnCl2 (stannous chloride) is formed. With hydrochloric acid, hydrated stannous chloride (SnCl2.2H2O) results.

With dry chlorine gas (Cl2) it unites to form anhydrous stannic chloride (SnCl4).

Tin metal reacts very vigorously with mixtures of hydrochloric acid and nitric acid (so called Aqua Regis) to form a solution of H2SnCl6. Caution: due to the fineness of this grade only small amounts of this powder should be added one at a time to well stirred Aqua Regis because the reaction can be violent and lead to boil-overs.

Tin metal is a mild reduction agent.

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CAS: none

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Potassium Thiocyanate - KSCN - Chemically pure - 100 g

Chemical formula: KSCN

Synonyms: potassium rhodanide, potassium sulphocyanide, potassium thiocyanide

Amount: 100 g

Appearance and odour: white powder without any appreciable odour

Packaging: professional wide necked, white HDPE bottle with blue conical seal cap and tamper ring. Labelled. Bottle and cap are UN approved and reusable.

Description and uses: an important pseudohalide compound, highly soluble in water and soluble also in acetone.

With Fe3+(aq) (ferric ion) it forms a blood red complex; FeSCN2+, a property used in analytical chemistry as a visual test for ferric ions. A KSCN solution is used in volumetric analysis as an indicator solution for redox titrations, using acidified ferric ammonium alum as titrant solution.

The red colour of the FeSCN2+ complex causes KSCN to be used for creating blood effects for film or theatre.

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CAS: 333-20-0

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Thursday, 25 August 2011

Potassium Bromide - KBr - Chemically pure - 100 g

Chemical formula: KBr

Synonyms: bromide of potassium

Amount: 100 g

Appearance and odour: white powder without any appreciable odour

Packaging: professional wide necked, white HDPE bottle with blue conical seal cap and tamper ring. Labelled. Bottle and cap are UN approved and reusable.

Description and uses: bromine’s main water soluble compound.

With chlorine gas or by electrolysis the bromide is converted to elemental bromine (Br2), a toxic dark red- brown liquid with an exceedingly pungent smell.

Potassium bromide is a precursor to potassium bromate (KBrO3), a very powerful oxidising agent.

In organic synthesis KBr is used to produce brominated species by acid-catalysed bromination of alcohols.

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CAS: 7758-02-3

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Potassium Iodide - KI - Chemically pure - 100 g

Chemical formula: KI

Synonyms: iodide of potassium

Amount: 100 g

Appearance and odour: white powder without any appreciable odour

Packaging: professional wide necked, white HDPE bottle with blue conical seal cap and tamper ring. Labelled. Bottle and cap are UN approved and reusable.

Description and uses: iodine’s main water soluble compound.

This grade shows no signs whatsoever of oxidation: pure white KI contains no free iodine (I2, which causes KI to take on a yellow hue).

With chlorine gas or by electrolysis the iodide is converted to violet elemental iodine (I2).

Elemental iodine is highly soluble in KI solutions forming potassium triiodide (KI3).

With copper (cupric) salts, insoluble cuprous iodide (CuI) and elemental iodine is formed:

Cu2+(aq) + 2 I-(aq) === > CuI(s) + ½ I2(aq)

This reaction is used in analytical chemistry to standardise oxidising solutions like sodium thiosulphate (Na2S2O3), by back titrating the iodine released by reacting a precisely known quantity of cupric salt with an excess of KI.

Iodine is an essential part of our diet. Iodine supplements (in the form of potassium iodide) are used to fight certain diseases. Iodine supplements are also administered in areas afflicted by nuclear disasters to substitute any intake of radioactive iodine 135.

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CAS: 7681-11-0

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Friday, 19 August 2011

Iron (II) Sulphate Heptahydrate - FeSO4.7H2O - 200 g

Chemical formula: FeSO4.7H2O

Synonyms: Ferrous sulfate; green vitriol; iron vitriol; copperas

Amount: 200 g

Appearance and odour: small green crystals without appreciable odour.

Packaging: professional wide necked, white HDPE bottle with blue conical seal cap and tamper ring. Labelled. Bottle and cap are UN approved and reusable.

Description and uses: a good source of Fe2+ (ferrous - oxidation state II) ions. This grade is highly and completely water soluble. It’s the basis of many Fe (II) salts. Oxidises easily to Fe (III), even by air. Precipitate with alkali, redissolve in acid to obtain other iron salts.

Note that this is not a common garden grade (moss killer), most of which contain anti-caking agents and show signs of partial oxidation and poor water solubility.

A mild reducing agent, common oxidisers like oxygen, nitric acid, chlorine, hydrogen peroxide and many others oxidise Fe (II) to Fe (III) and this is the basis for the production of many ferric (III) compounds.

At close to 500 Celsius in air it decomposes undergoing oxidation with sulphur dioxide and trioxide being liberated.

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CAS: 7720-78-7

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Thursday, 18 August 2011

Sodium Bisulphate - Sodium Hydrogen Sulphate - NaHSO4 - 200 g

Chemical formula: NaHSO4 (anhydrous)

Synonyms: sodium hydrogen sulphate, acid sodium sulphate

Amount: 200 g

Appearance and odour: small white crystals without appreciable odour.

Packaging: professional wide necked, white HDPE bottle with blue conical seal cap and tamper ring. Labelled. Bottle and cap are UN approved and reusable.

Description and uses: sometimes referred to as 'the poor man's concentrated sulphuric acid’, sodium bisulphate can be used to fuse with materials (minerals, ores, oxides...) to digest them (for analysis or extraction), instead of the more hazardous and generally more expensive concentrated sulphuric acid. The higher melting point (315 Celsius) allows reaching higher temperatures of fusion than mere digestion with sulphuric acid alone. Also when added to concentrated sulphuric acid it increases the latter’s boiling point, thus enabling to reach higher temperatures during difficult digestions of inorganic materials.

Prolonged heating at boiling point causes dehydration with formation of sodium pyrosulphate (Na2S2O7), a precursor to sulphur trioxide.

In aqueous solution it behaves like a medium-strong acid and will easily dissolve the more reactive of metals. A solution of 120 g/L (1 M) has a pH of less than 1. The bisulphate anion has a pKa of 1.99.

Industrially it finds use as ‘pH down’ to decrease the pH of water in a variety of applications.

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CAS: 7681-38-1

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Wednesday, 17 August 2011

Zinc Sulphate Heptahydrate - ZnSO4.7H2O - 200 g

Chemical formula: ZnSO4.7H2O

Synonyms: sulphate of zinc, white vitriol

Amount: 200 g

Appearance and odour: small, white crystals without appreciable odour.

Packaging: professional wide necked, white HDPE bottle with blue conical seal cap and tamper ring. Labeled. Bottle and cap are UN approved and reusable.

Description and uses: zinc sulphate heptahydrate is probably the most used general purpose, water soluble zinc compound and a precursor to most other zinc salts.

Precipitate as hydroxide using alkali and redissolve in relevant acid to obtain other salts of zinc. In an excess alkali the hydroxide redissolves as zincate. The hydroxide also dissolves in ammonia solution, forming a colourless zinc (II) tetra ammonium complex. This distinguishes it from aluminium which forms aluminates but not ammonia complexes.

The Daniell Cell is a textbook example of electrochemistry. A zinc anode dipped in a zinc sulphate solution and connected to a copper cathode dipped into a copper sulphate solution (the electrolytes are connected by a salt bridge to complete the circuit) provides a voltage across the electrodes of approximately 1.1 V (Volt).

Industrial uses include electroplating of zinc and as a dye mordant.

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CAS: 7733-02-0

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Monday, 15 August 2011

Iron (III) Oxide - Ferric Oxide - Fe2O3 - 200 g

Chemical formula: Fe2O3

Synonyms: ferric oxide, oxide of iron, red iron oxide, hematite

Amount: 200 g

Appearance and odour: red-brown fine powder without appreciable odour.

Packaging: professional wide necked, white HDPE bottle with blue conical seal cap and tamper ring. Labeled. Bottle and cap are UN approved and reusable.

Description and uses: iron’s main oxide. This is NOT a ‘pottery’ grade and as such has only negligible acid-insoluble residue.

A precursor to most other ferric (iron (III)) compounds by dissolving it in an excess of hot, conc. (> 95 %) sulphuric acid or by fusing it with an excess of sodium bisulphate.

Also find use in pyrotechnical applications and it’s one of the main components of Thermite. This mixture of ferric oxide and aluminium powder (often fluxes like fluorite are added to increase metal recovery) once ignited ‘burns’ (Goldschmidt Reaction) to sufficiently high temperatures (above 2,500 Celsius) to produce a mixture of molten alumina and molten iron metal, which separates out.

The Goldschmidt Reaction can also be used to produce valuable alloys and metal master batches (for addition to steel alloys) like ferrosilicon, ferrovanadium, ferrochromium, ferrotitanium, ferroniobium etc, by reacting aluminium powder with the relevant mixture of oxides.

Fused with KOH and KClO3, an unusual ruby red iron (VI) compound is formed: potassium ferrate (VI), a very strong oxidiser:

Fe2O3(s) + 4 KOH(l) + KClO3(s) --- > 2 K2FeO4(s) + KCl(l) + 2 H2O(g)

In neutral or acid conditions ferrate reduces to ferric (Fe (III)) ions.

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CAS: 1309-37-1

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Thursday, 4 August 2011

Ammonium Alum - Recrystallised - 100 g

Chemical formula: NH4Al(SO4)2.12H2O

Synonyms: ammonium aluminium sulphate dodecahydrate, double salt of ammonium sulphate and aluminium sulphate, aluminium sulphate (misnomer).

Amount: 100 g

Appearance and odour: mostly medium size white crystals, without appreciable odour

Packaging: professional wide necked, white HDPE bottle with blue conical seal cap and tamper evidence ring. Labelled. Bottle and cap are UN approved and reusable.

Description and uses: a double salt of aluminium sulphate and ammonium sulphate, NOT to be confused with its potassium homologue - alum - or with ferric ammonium alum - both also on sale from us. Used as a dye mordant and water treatment agent (flocculant) it is a primary source of soluble aluminium salt. Poorly soluble in iced water but highly soluble in hot water it is an ideal substance for crystal growing. It forms regular octahedral crystals with flattened corners and can be grown into very larger crystals with some patience. Mixed crystals with chromium alum or ferric alum can also be grown.

It belongs to the class of MM’(SO4)2.12H2O alum double salts, here with M = NH4 and M’ = Al.

Add ammonia solution to an alum solution and hydrated aluminium hydroxide precipitates: the basis of most other aluminium salts. Add strong alkali (NaOH or KOH) to the precipitate and it dissolves to aluminate, a phenomenon known as amphoterism.

Pyrolysis of this compound leaves pure alumina (Al2O3) behind.

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CAS: 7784-26-1
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Monday, 18 July 2011

Ammonium Hexachlorostannate - Pink Salt - 50 g

Chemical formula: (NH4)2SnCl6

Synonyms: pink salt, ammonium hexachlorostannate (IV)

Amount: 50 g

Appearance and odour: off-white crystals without appreciable odour.

Packaging: professional wide necked, white HDPE bottle with blue conical seal cap and tamper ring. Labelled. Bottle and cap are UN approved and reusable.

Description and uses: so called ‘pink salt’ because it was once used as a dye mordant for vivid pink colours with dyes like Madder and Cocheneal.

For chemists ammonium hexachlorostannate is a tin (IV) [stannic] coordination complex compound with some interesting properties.

Like many ammonium salts it’s very soluble in water. It’s a salt of a strong acid, H2SnCl6 (hexachlorostannic acid, which can be isolated as crystalline H2SnCl6.2H2O), and its solution in water is slightly acidic (from the ammonium ions). In hot, pure water hydrolysis of the anion tends to occur, with stannic hydroxide (Sn(OH)4) causing cloudiness of the solution. It’s therefore better dissolved in slightly acidified water (0.1 M HCl e.g.)

Ammonium hexachlorostannate is very soluble in 1 M HCl, both hot and cold. At BP the solubility in 1 M HCl is about 38 g/100 g. But in concentrated HCl (>20 %), both hot and cold, it’s solubility is very low, offering an easy route to recrystallisation.

The salt demonstrates the amphoterism of stannic compounds: add ammonia (or weak NaOH) to its solution and Sn(OH)4 precipitates. This precipitate redissolves both in strong acid (forming stannic salts) and in strong alkali (forming stannates - e.g. Na2Sn(OH)6).

Ammonium hexachlorostannate solutions are mild oxidisers: aluminium, zinc or magnesium metal will all be oxidised quickly with the tin being reduced to stannous (Sn (II)), which can be titrated with KMnO4 (e.g. for assaying purposes).

The pure compound, when heated strong in a hot Bunsen flame, sublimes leaving no ash: presumably the compound splits into NH4Cl and SnCl4 which are both volatile.

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CAS: 16960-53-5

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Saturday, 16 July 2011

Phenolphtalein Biodiesel Titration Indicator - 50 ml

Composition: solution of phenolphthalein in alcohol/water mixture.

Synonyms: phenolphtalein indicator solution for acid-base titrations.

Amount: 50 ml

Appearance and odour: clear liquid with alcoholic odour.

Packaging: professional white HDPE 50 ml dropper bottle with screw-on conical protective cap. Labelled.

Description and uses: high grade phenolphtalein based acid-base indicator solution. Add about three drops of indicator solution to any acid base titration and the titrated liquid will change colour from colourless to fuchsia (pink) from pH 8.2 to pH 10.

This so-called ‘pH interval' makes phenolphthalein indicator solution the preferred indicator for titrating waste vegetable oil with potassium hydroxide (KOH or ‘catalyst’) for biodiesel production from waste vegetable oil) solution.

Titrate 1 ml of waste vegetable oil dissolved in pure alcohol or 90 % rubbing alcohol (isopropanol - IPA) drop-wise with a solution that contains 1.00 g per litre of biodiesel catalyst (KOH) until the colour change from clear to pink occurs. Note the number of ml of KOH solution needed to get the colour change and add 7 to this number. That number is the amount of gram of KOH your vegetable oil will need to be converted to biodiesel fuel, using methanol, per litre of oil.

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CAS: 77-09-8 (pure phenolphthalein)
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Biodiesel Titration KOH Solution - 500 ml

Composition: Solution of biodiesel grade KOH in deionised water, 1.000 g KOH per litre.

Synonyms: biodiesel KOH titrant solution.

Amount: 500 ml

Appearance and odour: clear liquid without appreciable odour.

Packaging: professional narrow (picture shows a wide necked bottle) necked white HDPE 500 ml bottle with blue conical seal cap and tamper ring. Labelled. Bottle and cap are UN approved and reusable.

Description and uses: titrant solution of 1.000 g biodiesel grade solution per litre of deionised water.

Never ever worry again about accurately weighing 1.00 g of KOH and dissolving it in an accurate amount of 1000 ml of water! We prepare much larger batches to ensure high gravimetric and volumetric accuracy, with consequently more precise and better reproducible biodiesel titration results. The designed-for-liquids and chemically resistant UN approved HDPE bottle with conical seal means your KOH solution can be kept indefinitely.

Titrate 1 ml of waste vegetable oil dissolved in pure alcohol or 90 % rubbing alcohol (isopropanol - IPA) drop-wise with our biodiesel titrant solution (KOH 1.000 g/litre) until the colour change from clear to pink occurs. Note the number of ml of KOH solution needed to get the colour change and add 7 to this number. That number is the amount of gram of KOH your vegetable oil will need to be converted to biodiesel fuel, using methanol, per litre of oil.

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CAS: 1310-58-3 (pure KOH)

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Sunday, 10 July 2011

Aluminium Atomised spherical - 400 Mesh - 99.7 % - 200 g

Chemical formula: Al

Synonyms: aluminium powder, aluminum powder.

Amount: 200 g

Appearance and odour: very fine grey powder, without appreciable odour.

Packaging: professional wide necked, white HDPE bottle with blue conical seal cap and tamper ring. Labelled. Bottle and cap are UN approved and reusable.

Description and uses: this is a top notch grade, both in purity and fineness (400 mesh, 32 micron) suitable both pyrotechnical uses as well as various inorganic and organic synthesis. Ideally suited for super hot, lightening fast Thermite type reactions (Goldschmidt reactions).

Due to its high purity this product is very suited for direct halogenation either with chlorine of hydrogen chloride, to obtain anhydrous aluminium chloride, an important catalyst in Friedel-Crafts alkylation reactions.

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Saturday, 9 July 2011

Tin Chloride - Tin (II) Chloride - Reagent Grade - 50 g

Chemical formula: SnCl2.2H2O

Synonyms: tin chloride dihydrate, tin dichloride, stannous chloride, chloride of tin.

Amount: 50 g

Appearance and odour: white crystals, without appreciable odour.

Packaging: professional wide necked, white HDPE bottle with blue conical seal cap and tamper ring. Labelled. Bottle and cap are UN approved and reusable.

Description and uses: the primary and highly soluble water soluble tin (II) salt.

Ammonia solution added to a tin (II) chloride solution causes tin (II) hydroxide to precipitate. Adding strong alkali (NaOH or KOH) to the precipitate causes it to dissolve to stannite solution. Dissolving thin (II) hydroxide in acids causes the respective tin salts to be formed.

It’s a mild reducing agent that is easily oxidised to tin (IV) (stannic compounds) by oxygen, nitric acid and many other oxidising agents. It reduces copper (II) compounds to copper (I). By reduction of silver (I) solutions with SnCl2, silver mirrors can be created.

Electrolysis of aqueous stannous chloride solutions causes metallic tin to form at the cathode, often in the form of a so-called ‘tin-tree’.

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CAS: 10025-69-1

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Ammonium Chloride - Salmiac - 200 g

Chemical formula: NH4Cl

Synonyms: sal ammoniac, salmiac, nushadir salt, sal armagnac, salt armoniack

Amount: 200 g

Appearance and odour: white crystals, with slightly aromatic odour.

Packaging: professional wide necked, white HDPE bottle with blue conical seal cap and tamper ring. Labelled. Bottle and cap are UN approved and reusable.

Description and uses: a highly soluble water soluble ammonium salt that yields slightly acidic aqueous solutions.

At 338 Celsius it sublimes (evaporates without prior melting).

Ammonium chloride has a wide range of application fields such as chemistry, medicine, biology, metalwork, cryogenics, dry batteries and others.

Salmiac solutions combined with ammonia solutions form acid-base buffers (pH around 9).

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CAS: 12125-02-9

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Friday, 8 July 2011

Sodium Sulphite - Na2SO3 - 97 % - 200 g

Chemical formula: Na2SO3

Synonyms: anhydrous sodium sulphite

Amount: 200 g

Appearance and odour: white crystals, with slight sulphurous odour.

Packaging: professional wide necked, white HDPE bottle with blue conical seal cap and tamper ring. Labelled. Bottle and cap are UN approved and reusable.

Description and uses: the water soluble sodium salt of sulphurous acid (H2SO3).

A mild reducer it finds use as such in many industrial and laboratory applications.

Combined with a strong acid it releases gaseous sulphur dioxide (SO2).

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CAS: 7757-83-7

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Strontium Carbonate - SrCO3 - 98 % - 100 g

Chemical formula: SrCO3

Synonyms: carbonate of strontium.

Amount: 100 g

Appearance and odour: white crystalline powder, without appreciable odour

Packaging: professional wide necked, white HDPE bottle with blue conical seal cap and tamper ring. Labeled. Bottle and cap are UN approved and reusable.

Description and uses: an acid soluble strontium compound. Used in a plethora of inorganic and organic synthesis. Confers a typical carmine colour to a hot flame (bunsen or alcohol), due to strontium’s spectral emission lines. Like many carbonates it is highly insoluble in water.

An all round precursor to most strontium salts: just dissolve in the acid of choice to obtain the salt (carbon dioxide is the by-product).

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CAS: 1633-05-2

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Potassium Permanganate - KMnO4 - 99+ % - 100 g

Chemical formula: KMnO4

Synonyms: permanganate of potassium

Amount: 100 g

Appearance and odour: deep purple-brown crystals without appreciable odour.

Packaging: professional wide necked, white HDPE bottle with blue conical seal cap and tamper ring. Labelled. Bottle and cap are UN approved and reusable.

Description and uses: one of the most commonly used strong oxidisers, for non-aqueous and aqueous use. As an oxidiser it's fairly comparable to potassium dichromate.

In potassium permanganate, manganese finds itself in oxidation state +VII, its highest possible. A powerful oxidising agent, during the oxidation process Mn +VII gets reduced to Mn +II (Mn 2+ salts) or Mn +IV (MnO2, insoluble manganese dioxide), depending on conditions. Like potassium dichromate it can oxidise primary alcohols (to acids) and secondary alcohols (to aldehydes) with considerable generation of heat.

In the dry state potassium permanganate oxidises the alcohol functions of glycerine with the mixture heating up so much that it can be used to ignite a Thermite reaction: drop pipette some glycerine on to a small pile of potassium permanganate and it more or less catches fire.

Permanganate is also a source of other manganese salts, by-products of the oxidation process.

In analytical chemistry potassium permanganate is used abundantly for redox titrations, as an oxidising titrant solution (usually standardised against hot oxalic acid). This grade is pure enough for analytical purposes.

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CAS: 7722-64-7

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Potassium Chlorate - KClO3 - 99.9 % - 100 g

Chemical formula: KClO3

Synonyms: chlorate of potassium

Amount: 100 g

Appearance and odour: white crystals without appreciable odour.

Packaging: professional wide necked, white HDPE bottle with blue conical seal cap and tamper ring. Labeled. Bottle and cap are UN approved and reusable.

Description and uses: one of the most commonly used strong oxidisers, mainly for non-aqueous use. As such it finds extensive use in pyrotechnical applications, including solid rocket motors. It's a little less powerful than potassium perchlorate but safer to use.

With magnesium it forms a powerful flash powder. Ignite from a safe distance...

With aluminium powder it burns very hotly (probably over 3,000 centigrade) once ignited, usually with a magnesium ribbon or a blow torch, but in a very contained manner, producing (vapourised) KCl and molten alumina (Al2O3). For extra heat a little sulphur can be added but reportedly mixtures of KClO3, aluminium powder and sulphur (powder) are pressure sensitive and can flash. Due to high burn temperature, straight KClO3-Al powder mixes (stable enough to keep without any problems or special precautions) are a common method of igniting Thermite (Goldschmidt) reactions.

In some Thermite (Goldschmidt) reactions where extremely high end-temperatures are required (Niobium, Vanadium, Chromium, Titanium, special alloys) a certain amount of a stoichiometric mix of KClO3 and Al powder is added to the target oxide-Al powder mixture to boost heat output significantly and increase the yield of the high melting target metal.

KClO3 is also a handy laboratory source of small amounts of pure oxygen (O2): gently heated in a glass retort, the potassium chlorate releases its chemically bound oxygen, leaving behind potassium chloride (KCl).

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CAS: 3811-04-9

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Lead Nitrate - Pb(NO3)2 - chemically pure - 50 g

Chemical formula: Pb(NO3)2

Amount: 50 g

Appearance and odour: white crystals without appreciable odour.

Packaging: professional wide necked, white HDPE bottle with blue conical seal cap and tamper ring. Labeled. Bottle and cap are UN approved and reusable.

Description and uses: lead nitrate is probably the most used general purpose, highly water soluble lead compound and a precursor to most other lead salts and compounds.

This product is sufficiently pure to be used as a standard material.

Precipitate as lead carbonate using sodium carbonate and redissolve in relevant acid to obtain other salts of lead.

A solution of lead nitrate can be oxidised to lead (IV) oxide (PbO2) with NaOH and sodium hypochlorite (commercial bleach). Dissolving the freshly prepared PbO2 in ice cold concentrated HCl and decanting this solution into an ice cold saturated solution of ammonium chloride (NH4Cl) causes yellow ammonium hexachloroplumbate ((NH4)2PbCl6) to crystallise out. This is a member of a group of compounds derived from Group IV (a or b) metals in oxidation state +IV with general formula M2M'X6, where M is an alkali cation (or ammonium), M' is a metal from Group IV in oxidation state +IV and X is a halogen. The hexachloroplumbate coordination complex releases oily PbCl4 (lead tetrachloride) when treated with cold concentrated sulphuric acid.

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CAS: 10099-74-8

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Nickel Sulphate - 99 % - 50 g

Chemical formula: NiSO4.7H2O

Synonyms: nickel sulphate heptahydrate, spirit of nickel.

Amount: 50 g

Appearance and odour: green crystals without appreciable odour.

Packaging: professional wide necked, white HDPE bottle with blue conical seal cap and tamper ring. Labelled. Bottle and cap are UN approved and reusable.

Description and uses: nickel sulphate heptahydrate is probably the most used general purpose, water soluble nickel compound and a precursor to most other nickel salts.

Precipitate as hydroxide using alkali and redissolve in relevant acid to obtain other salts of nickel.

Washing and glowing the hydroxide Ni(OH)2.nH2O and one obtains nickel (II) oxide (NiO) which can be reduced by various reducing agents, including aluminium powder in a Goldschmidt reaction. This reaction needs considerable amounts of calcium fluoride (Fluorite) to dampen its vigour and obtain nickel lump metal.

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CAS: 10101-98-1

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Copper Oxide - CuO - 100 g

Chemical formula: CuO

Synonyms: cupric oxide

Amount: 100 g

Appearance and odour: heavy, dark brown-black powder without appreciable odour.

Packaging: professional wide necked, white HDPE bottle with blue conical seal cap and tamper ring. Labeled. Bottle and cap are UN approved and reusable.

Description and uses: copper (II) oxide is used in pottery glazing as a greenish pigment. Chemically it is quite inert and requires hot concentrated sulphuric acid or fusing with sodium bisulphate to enter solution. It's precursor to copper metal.

It can be used to demonstrate the (industrial) use of carbon (cokes) as a reducing agent for metal oxides: a mixture of CuO and finely ground carbon is heated in a test tube with a hot Bunsen flame. Carbon reduces the oxide to metal and CO/CO2 is formed. Copper sponge is left behind.

Another reducing agent for copper (II) oxide is aluminium powder in a Thermite (Goldschmidt) reaction. Note that this reaction needs considerable calcium fluoride to obtain actual lump copper metal.

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CAS: 1317-39-1

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Phenol - Reagent Grade - 50 g

Chemical formula: C6H5OH

Synonyms: Carbolic Acid, Benzenol, Phenylic Acid, Hydroxybenzene, Phenic acid

Amount: 50 g

Appearance and odour: medium size clear crystals, with a distinct sweet odour.

Packaging: professional wide necked, white HDPE bottle with blue conical seal cap and tamper ring. Labelled. Bottle and cap are UN approved and reusable.

Description and uses: one of the most important precursors used in organic synthesis.

Slightly soluble in water, yields slightly acidic solutions.

An aromatic compound reactive towards electrophilic substitutions.

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CAS: 108-95-2

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Ultra fine Zinc Powder - 900 mesh - 99 % - 100 g

Chemical formula: Zn

Synonyms: zinc dust

Amount: 100 g

Appearance and odour: very fine dark powder, without appreciable odour.

Packaging: professional wide necked, white HDPE bottle with blue conical seal cap and tamper ring. Labeled. Bottle and cap are UN approved and reusable.

Description and uses: Ultra fine zinc powder (2 - 3 micron!) of high chemical purity.

To a first user of this product the powder may appear quite lumpy, thereby hiding its ultrafine nature. Fine powders tend of course to somewhat clump together and the powder of a fairly soft, reactive and quite pure metal like zinc is no exception. Very gently crushing the product on a smooth but hard surface and pestle, dispersion into a dry mix or dispersion into a liquid by means of vigorous stirring will cause any aggregates to completely break up.

In inorganic and organic chemistry zinc powder finds use as a powerful reducer, during which it oxidises to Zn (+II) which can be complexed (for separation purposes) with ammonia.

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Bismuth Nitrate - 100 g - 99.5 % - Lab grade

Chemical formula: Bi(NO3)3.5H2O

Synonyms: bismuth nitrate pentahydrate, nitrate of bismuth.

Amount: 100 g

Appearance and odour: white crystals without appreciable odour

Packaging: professional wide necked, white HDPE bottle with blue conical seal cap and tamper ring. Labeled. Bottle and cap are UN approved and reusable.

Description and uses: a water soluble bismuth compound, prone to hydrolysis. A precursor for other bismuth compounds. This is a high grade of bismuth nitrate.

Dispatch: depending on time of receipt of your order, your item will be dispatched either same day or next day at the latest.

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CAS: 10035-06-0

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Barium Carbonate - 100 g - BaCO3

Chemical formula: BaCO3

Synonyms: carbonate of barium.

Amount: 100 g

Appearance and odour: white powder, without appreciable odour.