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Chemistry infolab reagents and resources
The preparation of reagents for inorganic qualitative analysis

Bench, side-bench, and special reagents

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Laboratory Reagents for Qualitative analysis

This page gives info on the preparation of the laboratory reagents and solutions
used in analytical qualitative analysis

SIDE BENCH REAGENTS

General reagents
Special reagents

General reagents

Ammonium acetate.
Dissolve 231 g of the salt in 1 liter of water. (3M)
Ammonium carbonate.
The commercial salt is a mixture of bicarbonate and carbamate. Dissolve 192 g of the salt in a mixture of 140ml conc. ammonia solution and water to make up 1 liter of solution. (2M)
Ammonium chloride
dissolve 169 g of the salt in 1 liter of solution (3M).
Ammonium nitrate
dissolve 80 g of the salt in 1 liter of water. (1M)
Ammonium oxalate
dissolve 71 g of the crystaline salt in 1 liter of water.(0.5M)
Ammonium sulphate
dissolve 132 g of the salt in 1 liter of water.(1M)
Ammonium sulphide
use the yellow commercial product
Ammonium thiocyanate
Dissolve38 g of the salt in 1 liter of water (0.5M)
Barium chloride
dissolve 61 g of the salt in 1liter of water.(0.25M)
Bromine water
a saturated aqueous solution is prepared by shaking 35g or 11ml liquid bromine with water. Add more bromine if necessary to a slight excess.
Calcium chloride
dissolve 55 g of the hydrated salt in 1 liter of water (0.25M)
Calcium sulphate
shake 3 g of the salt with 1 liter of water, filter and decant the saturatrd solution after several hours (0.015M)
Chlorine water
saturate 250ml of water with chlorine.the chlorine may be prepared by dropping conc. HCl upon KmnO4. Preserve in a dark coloured bottle.(6.8g/l)
Cobalt nitrate
dissolve 44 g of the salt in 1 liter of water. (0.15M)
Copper sulphate
dissolve 125 g of the salt in 1 liter of water containing 3ml of conc. Sulphuric acid.(0.5M)
Ferric chloride
dissolve 135 g of the hydrated salt in 1 liter of water containing 20ml of conc. HCl (0.5M)
Ferrous sulphate
dissolve 140 g of the salt in 1 liter of water containing 7 ml of conc. Sulphuric acid (0.5M)
Hydrogen sulphide
H2S generated from a Kipps apparatus ( ~42g/l)
Iodine solution
dissolve 12.7 g of iodine in a solution of 20g of pure KI in 30 ml of water, and dilute to 1 liter with water.(0.05m)
Lead acetate
dissolve 95 g of the salt in 1 liter of water (0.25M)
Magnesium sulphate
dissolve 62 g of the salt in 1 liter of water (0.25M)
Magneson (4-(4-nitrophenylazo) resorcinol
0.001% in 1M NaOH.
Mercuric chloride
dissolve 27 g of the salt in 1 liter of water (0.1M)
Potassium chromate
dissolve 49g of the salt in 1 liter of water (0.25M)
Potassium ferricyanide
dissolve 55 g of the salt in 1 liter of water (0.25M)
Potassium ferrocyanide
dissolve 53 g of the salt in 1 liter of water (0.125M)
Potassium iodide
dissolve 83 g of the salt in 1 liter of water (0.5M)
Potassium permanganate
dissolve 3.2g of the salt in hot water, dilute to 1 liter, and filter through glass wool (0.01M)
Potassium thiocyanate
dissolve 49g of the salt in 1 liter of water (0.25M)
Silver nitrate
dissolve 17g of the salt in 1 liter of water (0.1M)
Silver sulphate
dissolve 8g of the salt in 1 liter of water. this is nearly a saturated solution (0.025M)
Sodium acetate
dissolve 408g of the crystaline salt in 1 liter of water (3M)
Sodium carbonate
dissolve 430g of the crystaline salt in 1 liter of water (1.5M)
Disodium hydrogen phosphate
dissolve 120g of the salt in 1 liter of water 0.34M)
Stannous chloride
dissolve with heat 56g of the salt in 100ml conc. HCl and dilute to 1 liter. Keep a few pieces of granulated zinc in the stored solution to avoid oxidation. (0.25M)
Thiourea
10g in 100ml of water (10%)
Titan yellow
dissolve 1g in 100ml of water (1%)
Zinc nitrate
dissolve 150g of the salt in 1 liter of water (0.5M)




SPECIAL REAGENTS


B     C     D     E     F     G     H    I     J     K     L     M     N     O     P     Q     R     S    T    

U     V     W     X    Y     Z        


A

Aluminon
Use a 0.1% aqueous solution.
Alizarin
Make a saturated solution in ethanol.
Alizarin-S
Sodium alizarin sulphate
Use a 0.1% aqueous solution.
1-Amino-1-Naphthol-4-sulfonic acid
Dissolve 0.2 g in 195 ml of sodium bisulphite solution (3 in20) and 5 ml of anhydrous sodium sulphite solution (1 in 5) and filter if necessary. Stopper and store in a cool dark place. Use within 10 days.
Ammoniacal silver nitrate.
Add conc ammonia to bench silver nitrate (0.1M) until the initially formed ppt. Just disappears.
Ammonium citrate, lead free
Dissolve 40g of citric acid in 100 ml of water and make alkaline to phenol red with ammonium hydroxide. Remove lead by shaking with small portions of dithizone extraction solution in chloroform until the dithizone solution retains its original green color.Discard the extraction solution.
Ammonium mercurithiocyanate
Dissolve 9g of ammonium thiocyanate and 8g of mercuric chloride in 100ml of watwer.
Ammonium metavanadate
Dissolve 2.5g of NH4VO3 in 500 ml of boiling water, cool, and add 20 ml of nitric acid. Dilute to 1 liter and store in polythene bottle.
Ammonium molybdate reagent
Method A: Dissolve 45 gms. of the commercial salt or 40 gms. of pure molybdenum trioxidein a mixture of 70 ml.of concentrated ammonia solution and 140 ml. of water; when solution is complete, add it very slowly and with vigorous stirring to a mixture of 250ml.of concentrated nitric acid and 500ml.of water, and dilute to 1 litre.Allow to stand 1 to 2 days and decant and use the clear solution.
Method B: Dissolve 45 gms. of pure commercial ammonium molybdate in mixture of 40ml. concentrated ammonia solution and 60 ml. of water, add 120gms. of ammonium nitrate and dilute to a litre with water.
Note: The alkaline solution of ammonium molybdate keeps better than the nitric acid solution; there is little tendency for the separation of solid. Before using the alkaline solution, it is important that the test solution contains a slight excess of nitric acid.
Ammoniacal silver nitrate
Add ammonia dropwise to a 1 in 20 solution of silver nitrate until the ppt. that first forms is almost , but not entirely, dissolved. Filter and store in dark bottle.Forms explosive compounds on standing! Prepare fresh.
Ammonium sulfanilate
To 2.5 g of sulfanilic acid add 15 ml water and 3 ml ammonia and mix. If necessary add more ammonia until the the acid dissolves. Adjust the pH to 4.5 with dilute HCl and dilute to 25 ml.
Amylase
To 0.2 g of amylase crystal, add 100ml water, shake well and filter. Prepare fresh.
Anthranilic acid
Dissolve 0.5g in 100 ml ethanol
Anthrone
Dissolve about 0.1 g in 100 ml sulphuric acid. Prepare fresh.
Aqua Regia
Mix one part by volume of conc. nitric acid with three (3) parts by volume of conc. hydrochloric acid in a pyrex beaker and allow to stand until a bright red color develops.

B

Barfords reagent
Dissolve 13.3gm.of crystalised neutral copper acetate in 200ml.of 1% acetic acid solution. This reagent does not keep well.
Bradys reagent (2,4 DNPH)
Dissolve 40g of 2, 4 dinitrophenylhydrazine in 80ml conc. Sulphuric acid. Cool and add 900ml methanol and 100ml water.
Benedicts solution (qualitative)
Dissolve 86.5gm.of sodium citrate and 50gm. of anhy. sodium carbonate in about 350ml. of water. Filter if necessary. Add a solution of 8.6gm. of copper sulphate in 50ml. of water with constant stirring. Dilute to 500ml. The resulting solution should be perfectly clear; if not, filter through a fluted filter paper.
Benedicts solution (quatitative)
Dissolve 200g sodium citrate, 75g sodium carbonate and 125g potassium thiocynate in about 600 ml water. Dissolve separately, 18g copper (11) sulphate in 100 ml water. When the solutions have cooled, mix them together with stirring. Now add 5 ml of a 5% potassium ferrocyanide to the solution, and make up to 1 liter.
Benzidine
Dissolve 50 g in 10 ml glacial acetic acid, dilute to 100 ml with water and mix. caution: Toxic!).
Benzodine
Dissolve 1g in 10ml acetic acid and dilute to 100 ml with water.
2,2-bipyridine
Dissolve 0.100 g in 50ml purified absolute ethanol.
Biuret reagent(qualitative)
Take enough urea to cover the bottom of a test tube. Heat very gently , until the liquid which forms resolidifies. This white solid is biuret. Dissolve the biuret in about 2ml. water, and use this solution for the biuret test.
Or
Soln. A : 0.1m sodium hydroxide.
SoLn. B : 0.01M copper (11) sulphate solution. Add soln. A first to sample, then add B. Pink or purple color confirms protein.
Biuret reagent (quantitative)
Dissolve in order, 3g copper (11) sulphate, 5g potassium iodide, 9g potassium sodium tartrate, and 8g sodium hydroxide in about 600 ml water. Make up the dissolved solids to 1 liter solution.
Brucine sulphate
Boil a 2 to 1 mixture of conc. sulphuric acid and water to to remove nitrates, cool , and dissolve into it 0.6g of brucine sulphate and dilute to 1 liter.

C

Carr-Price reagent
Weigh an unopened bottle of antimony trichloride. Open the bottle and empty the contents into a wide mouth glassstoppered amber bottle containing about 100 ml of chloroform. By difference, obtain the weight of antimony trichloride and then add sufficient chloroform to supply 100 ml for each 25 g. Dissolve by warming or shaking for several hours and filter through sodium sulphate into a dry clean amber bottle with ground stopper.Store at room temperature and keep in dark when not in use. Rinse all glassware coming into contact with this reagent wit chloroform or a mixture of ethanol and ether, since the antimony oxychloride which forms is insoluble in water.
Cacotheline
a-nitroso-b-naphthol reagent
Dissolve 0.25 g in 100 ml of water.
Cadion 2B reagent
4-nitronaphthalene-diazamino-azobenzene
Dissolve 0.25 g in 100 ml of water.
Chloroplatinic acid
Dissolve 2.7 g in 10 mls. of water.
Chromic acid
Weigh out 10 g of sodium dichromate crystals, make it into a slurry with a few mls of watwer, then dissolve in 250mls conc. sulphuric acid with stirring and cooling (ice-bath), to give a thick syrupy dark brown mixture.(very corrosive!)
Chromotrope 2B
Use a 0.005% in conc. sulphuric acid.
Chromotropic acid
Dissolve 1g of 4,5-dihydroxy-2,7-naphthalenedisulfonic acid in 100 ml water.
Cincholine
Dissolve 1g in 100 ml hot water containing a few drops of nitric acid, cool, and add 2g of KI.
Cobalt-uranyl acetate
Dissolve with warming, 40 g of uranyl acetate in a mixture of30 ml acetic acid and 470 ml water.Similarly, prepare a solution containing 200 g of cobaltous acetate in a mixture of 30 ml acetic acid and 470 ml water. Mix the two solutions while still warm, cool to room temperature to separate xs salts from the solution and filter.
Cupferon
Dissolve 5 g in 100ml solution.(5%) Does not keep. Add about 1g of ammonium carbonate to stock to enhance stability.
Cupron
Dissolve 5g of a-benzoin oxime in 100ml ethanol

D

Deniges reagent
Dissolve 5 g of yellow mercuric oxide (HgO) in a mixture of 40 ml of water,and while stirring slowly add 20 ml of sulphuric acid, then add another 40 ml of water, and stir until complety dissolved <0.5N)
Dimethyl glyoxime
Dissolve 1gm. of the solid in 100ml. of 95% ethyl alcohol.
N,N-dimethyl-p-phenylenediamine
a.
Measure and pour into a 250 mL beaker 89 mL of distilled water. Stir on a magnetic stirrer. Carefully add 15 mL of concentrated sulfuric acid. Add and dissolve 1.0 g n,n-dimethyl-p-phenylenediamine sulfate. Add 5 g of Florisil and stir the mixture until all is absorbed. Allow the adsorbant to settle and decant the supernatant solution.
b.
Add 200 ml sulphuric acid to 700 ml water, cool, and add 1g of N,N-dimethyl-p-phenylenediamine (p-aminodimethylaniline) and dilute ti 1 liter.
Dinitro-p-diphenylcarbazide Dissolve 0.1g in 100 ml ethanol
Diphenylcarbazide
Use a saturated ethanolic solution; or dissolve 0.125 g in a mixture of 25ml acetone 25 ml water; or dissolve 0.2g in 10 ml acetic acid and dilute to 100 ml with methanol
Diphenylcarbazone
Dissolve an approximately 1% solution in ethanol.
Dipicrylamine
Dissolve 0.2g in 20 ml of 0.1M sodium carbonate solution, boil, cool, then filter.
Dipridyl reagent
Dissolve 0.1g in 0.5ml ethanol,or in 0.1M HCl
Dithiol reagent
4-methyl-1:2 dimercarpo-benzene
Dissolve 0.2g in 100 ml of 1% NaOH
Dithizone solution
Dissolve 30 mg (milligram) of dithizone in 1 liter chloroform, add 5 ml alcohol, and store in refrigerator.
Dragendorff reagent
Solution 1: dissolve 0.85g of basic bismuth nitrate in 10 ml acetic acid and 40 ml water.
Solution 2: dissolve 8 g of potassium iodide in 20 ml water.
Mix 5 ml of Solution 1; 5 ml of Solution 2; 20 ml of acetic acid; and 100 ml of water before use.

E

Ethylenediamine reagent
Add copper sulphate to a solution of ethylenediamine until the color becomes dark-blue violet
p-Ethoxychrysoidin
Dissolve 50 g in a mixture of 25 ml water and 25 ml ethanol, add 3 drops hydrochloric acid, stirr vigorously, and filter if necessary to obtain a clear solution.

F

Fehlings solution
Solution A; Dissolve 34.6gms. of pure copper sulphate in distilled water and dilute to 500ml. ( blur )
Solution B: Dissolve 173gms. of sodium potassium tartrate and 30gms.of pure sodium hydroxide in water and dilute to 500ml. Alternately, dissolve 121gms. of pure sodium hydroxide and 93.1gms.of pure tartaric acid in water, then dilute the solution to 500ml.( colourless ).
Mix equal volumes of solutions A and B immediately before use, and then use as the reagent.
Ferric thiocyanate reagent
Dissolve 1.5 g of ferric chloride and 2.0 g of potassium thiocyanate in 100 ml water.
Ferron reagent
7-iodo-8-hydroxyquinoline-5-sulphonic acid
Dissolve 0.2 g in 100 ml water
Fluorescein
Make a saturated solution in 50% ethanol.
Formaldehyde
Dilute the commercial 40% solution (1 part) with water (7 parts)
Fuchsin solution
Dissolve 0.15gm. of fuchsin in 100ml. water.
Furil-dioxime reagent
Dissolve 10 g in 100 ml ethanol.

G H

Hydrazine sulphate
Dissolve 2 g in 100 ml water.
Hydrogen peroxide
Use the commercial 10 volume (3%) or 20 volume 6%) solution.
Hydroxylamine hydrochloride
Dissolve 10 g in 100 ml water.
8-Hydroxyquinoline
Use a 5% solution in ethanol.

I

Indigo solution
Gently warm 1gm. of indigo with 12ml. of concentrated sulphuric acid, allow to stand for 48hrs. and pour into 240ml. of water. Filter if necessary.
Indole
Dissolve 0.15 g in 100 ml ethanol
Iodine reagent.
Dissolve 20g KI and 10g iodine crystals in 100ml water.

J

Jones reagent.
Mix 25g of chromium trioxide (chromic anhydride CrO3) with conc. sulphuric acid to a paste, then dilute with water to 75mls.

K

Karl Fisher Reagent
Dissolve 762 g of iodine in 2,420 ml of pyridine in a 10 liter glass stoppered bottle, and add 6 liters of methanol. To prepare the active stock, add 3 liter of the foregoing stock to a 4 liter bottle, cool in ice bath. Add carefully 135 ml of liquid sulfur dioxide, collected in a calibrated cold trap,and stopper the bottle. Shake the mixture until homogeneous, and set aside for one or two days before use.

L M

Magnesia mixture
Dissolve 100gms. of magnesium chloride and 100gms.of ammonium chloride in water, add 50ml. of concentrated ammonia solution and dilute to 1 litre with distilled water.
Magnesium nitrate reagent
Dissolve 130gms. of magnesium nitrate and 200gms. of ammonium nitrate in water, add 15-20mls.concentrated ammonia solution and dilute to 1 litre.
Magneson 1
para-nitrobenzene-azo-resorcinol
Magneson 11
para-nitrobenzene-azo a-naphthol
Use a 0.001% in 1M sodium hydroxide.
Malachite green
A 1% solution of malachite green oxalate in glacial acetic acid.
Manganese sulphate
Dissolve 90 g manganese sulphate in 200 ml water, 175 ml phosphoric acid and 350 ml of diluted sulphuric acid (1 in2). Add water to make up 1 liter.
Mayers reagent
Mercuric-Potassium Iodide

Dissolve 1.358 g of mercuric chloride in 60 ml water. Dissolve 5 g of potassium iodide in 10 ml water. Mix the two solutions and add water to make 100 ml.
4-(methylamino)phenol sulphate
Dissolve 2 g in 10 ml water. To 10 ml of this solution add 90 ml of water and 20 g of sodium bisulfite.
Millons reagent
Warm one globule of Mercury with concentrated nitric acid and dilute the solution with twice its volume of water.
Molischs reagent.
20% soln. in naphthol. Dissolve 20g of 1-naphthol in 100ml ethanol.
Murexide
Add 0.4 g of murexide to 40 g of powdered potassium sulphate, and grind in glass mortar to a homogeneous mixture.

N

Naphthalenediol
Dissolve 0.1 g of 2,7-dihydroxynaphthalene in 1 liter sulphuric acid and allow the solution to stand in the dark until the yellow color has diappeared (at least 18 hrs.)
1-Naphthol
Dissolve 1 g of 1-naphthol in 25 ml methanol. Prepare fresh.
alpha-Naphtholbenzein
A 1% solution in benzol.
a-Naphthalamine
Boil 0.3 g in 70 ml water, filter or decant, and mix with 30 ml of glacial acetic acid.
Nesslers reagent
Dissolve 10gms. of potassium iodide in 10mls. of ammonia-free water, adding saturated mercuric chloride solution (60gms. / litre) in small quantities at a time with shaking, until a slight permanent precipitate is formed, then adding 80ml. of 9M sodium hydroxide solution and diluting to 200ml.Allow to stand overnight and decant the clear liquid.

Nesslers reagent has been described as a solution which is about 0.09M in potassium mercuri-iodide and 2.5M in potassium hydroxide.

An alternative method is to dissolve23gms. of mercuric iodide and 16gms. of potassium iodide in ammonia-free water and make up the volume to 100ml; add 100ml. of 6M sodium hydroxide. Allow to stand for 24hrs. and decant the solution from any precipitate that may have formed, the solution should be kept in the dark.

Another method that reacts promptly and consistantly is to dissolve 143 g of sodium hydroxide in 700 ml water. Disolve 50 g of red mercuric iodide and 40 g of potassium iodide in 200 ml water. Pour the iodide solution into the hydroxide solution, and dilute with water to 1 liter. Allow to settle, and use the supernatant liquid.
Ninhydrin
A 0.2% solution of ninhydrin (triketohydrindene hydrate, C9H4O3.H2O) in water. Prepare fresh.
Nitron reagent
Dissolve 5g nitron in5 ml acetic acid and make up to 100 ml with water.
a-Nitroso-b-naphthol
Dissolve 10 g in 100 ml of either 1:1 acetic acid , ethyl alcohol or acetone.
Nitroso-R-salt
sodium 1-nitroso-2-hydroxynaphthalene-3:6-disulphate
Dissolve 1 g in 100 ml water.

O

1,10-phenanthroline
Dissolve 0.1 g of the monohydrate in 100 ml water.
Orthophenanthroline
Dissolve 0.15 g orthophenanthroline (C12H8N2.H2O) in 10 ml solution of ferrous sulphate, prepared by dissolving 1.48 g of ferrous sulphate in 100 ml water. THe ferrous sulphate solution must be prepared immediately before dissolving the orthophenanthroline.

P

Phosphomolybdic acid
Dissolve 5 g in water, filter and dilute to 100 ml.
Picric acid
Dissolve the equivalent of 1 g of anhydrous trinitrophenol in 100 ml of hot water. Cool, and filter if necessary.
Potassium cyanide
Dissolve 10 g of KCN in sufficient water to make 20 ml. Dilute to 100 ml. Shake with dithizone solution to remove lead.
Pyrogallol
1:3:5-trihydroxybenzene

Q

Quimociac reagent
Dissolve 70 g of sodium molybdate (Na2MoO42H2O) in 150 ml water (Slution A). Dissolve 60 g of acetic acid in a mixture of 85 ml nitric acid and 150 ml of water and cool (Solution B) Gradually add Solution A to Solution B, with stirring, to produce Solution C. Dissolve 5 g of synthetic quinoline in a mixture of 35 ml nitric acid and 100 ml water (Solution D) Gradually add Solution D to Solution C, mix well, and allow to stand overnight. Filter the mixture, add 280 ml of acetone to the filtrate, dilute to 1 liter with water, and mix. Store in polythene bottle.(Caution: Flammable).
Quinaldic acid
Neutralize 1g of the acid with NaOH and dilute ti 100 ml
Quinalizarin reagent
Dissolve 0.02g in 100 ml ethanol, or dissolve 0.05g in 100 ml of 0.01M sodium hydroxide.

R

Rhodamine B
Dissolve 0.01 g in 100ml water, or dissolve 0.05 g rhodamine B and 15g KCL in a solution of 15 mls conc. HCl and 85 mls water
Rubeanic acid
(dithio-oxamide) - 0.05% in ethanol., a saturated ethanolic solution.

S

Salicylaldehyde
A 20% solution in ethanol.
Schiffs reagent
Method 1: Dissolve 0.2gm. of pure p rosaniline hydrochloride in 20ml. of a cold, freshly prepared, saturated aqueous solution of sulphur dioxide; allow the solution to stand for a few hours until it becomes colourless or pale yellow. Dilute the solution to 200ml. and keep it in a tightly stoppered bottle.The solution keeps well, and should not be exposed to light or air. Store in the dark.
Method 2: Add 2gm. of sodium bisulphite to a solution of 0.2gm.of p- rosaniline hydrochloride and 2ml.of concentrated hydrochloric acid in 200ml. of water.
Silicotungstic acid
Dissolve 10 g ofsilicotungstic acid (Si02.12WO3.26H2O) in water and neutralize with 10% sodium hydroxide (pH 6)
Silver ammonium nitrate
Dissolve 1 g of silver nitrate in 20 ml of water.Add ammonia dropwise, withconstant stirring, until the ppt. is almost but not entirely dissolved. Filter and store in dark container.
Silver diethyldithiocarbamate
Dissolve 1 g in 200 ml of freshly distilled pyridine.
Sodium azide
A 5% solution of sodium azide in water.
Sodium borohydride
Dissolve 0.6 g sodium borohydride and 0.5g of sodium hydroxide with stirring and dilute to 100 ml with water.
Sodium diethyldithiocarbamate
Dissolve 1 g in water and dilute to 1 liter.
Sodium cobaltinitrite solution
Dissolve 17gms. of the pure salt in 250
of water.
Alternately, the solution may be prepared as follows: Dissolve 7.5 gms. cobalt nitrate in 30ml. of water; dissolve 60gms. of sodium nitrite in 30ml. of water, mix the two solutions with vigorous stirring and add 15ml. of glacial acetic acid, stir, dilute to 250ml, allow to stand and filter.Make up new solution every 2-3 weeks.
Sodium ethoxide
Dissolve 10 g of sodium metal in 120 ml of ethanol using the following method: remove surplus oil from sodium with filter paper, dry again on filter paper, and cut the weighed metal into small pieces about the size of a pea. pour the ethanol into a 500 ml flask cooled on ice bath, and add one or two pieces at a time until dissolved.
Sodium hypochlorite solution
The commercial product contains about 10-14 per cent w / v of available chlorine. Dilute with an equal volume of water.
Sodium nitroprusside solution
Prepare a solution as required by dissolving a crystal in 5 ml. of water.
Sodium rhodizonate reagent
Dissolve 0.5 g in 100 ml water
Starch solution
Triturate 0.5gm. of soluble starch with a little cold water into a thin paste and add 25ml. of boiling water.Boil until a clear solution is obtained (5-mins.). This solution should be freshly prepared as required. Amore stable starch solution is obtained by adding 0.5gm. of potassium iodide and 2-3 drops of chloroform.
A more satisfactory starch solution for use as an indicator is prepared as follows:* Mix 5.0 gm.of powdered sodium starch glycollate with 1-2 ml. ethyl alcohol, add 100ml. of cold water and boil for a few minutes with stirring.This 5% stock solution is stable for many months; it is diluted to 0.1% strength when required for use.
Sulphanilic acid
Dissolve 1 g in 100 ml of warm 30% acetic acid

T

Tannic acid
Dissolve 1 g of tannic acid (tannin) in 1 ml ethanol, and add water to make 10 ml. Prepare fresh.
Tartrate solution, alkaline
Dissolve 34.6 g of sodium potassium tartrate (rochelle salt) and 10 g of sodium hydroxide in water, dilute to 100 ml, let stand for two days, and filter through glass wool.
Thiourea
10g in 100ml of water (10%)
Titan yellow
Dissolve 1g in 100ml of water (1%)
or
Titan yellow
(also called thiazole yellow, clayton yellow)
Dissolve 5 g in water, filter and dilute to 100 ml.
Titanium tetrachloride
Cool separately in small beakers surrounded by crushed ice 10 ml of 20% hydrochloric acid and 10 ml of clear, colorless titanium tetrachloride.Add the tetrachloride dropwise to the chilled acid.Stand at ice temperature until all the solid disolves, then dilute to 1 liter with 20% hydrochloric acid.
Tollens reagent.
Add sodium hydroxide soln. to silver nitrate soln. to form a ppt. then add dilute ammonia soln. until ppt. Dissolves.
Triton X-100
20% solution: dissolve 0.20 g of Triton-X-100 (polyethelene glycol ether of isooctylphenol) in water, and dilute to 100ml.

U

Uranyl magnesium acetate
Make up an aqueous saturated solution of the salt.

V W X

Xylenol orange
Make up a 1% solution in ethanol
Y Z

Zirconyl nitrate reagent
( for fluoride test )
Dissolve 0.1gm. of zirconyl nitrate in 20ml. concentrated hydrochloric acid and dilute with water to 100ml.
Zirconyl nitrate reagent
( for phosphate separations )
Heat 10gms. of commercially pure zirconium nitrate and 100ml. of 1M nitric acid to the boiling point with constant stirring.Leave to stand for about 24hrs.and decant the clear solution.
Zinc amalgam
Add about 10 g of granulated zinc to to 20 ml mercury, to produce a liquid amalgam on cooling, and heat to 150 degrees with stirringuntil the zinc is dissolved.
Zinc amalgated (Jones Reductor)
The zinc is amalgated by immersing it in a solution of mercuric chloride in hydrochloric acid. A quantity of 250 g of 20 mesh zinc is covered with water in a 1 liter flask, and a solution of 11 g of mercuric chloride in 100 ml of hydrochloric acid is poured into the flask. The system is slowly mixed and shaken for about 2 minutes. The solution is poured off, and the amalgam is washed thoroughly with hot tap water, then distilled water.
Zinc uranyl acetate
Dissolve 10gms. of uranyl acetate in 6gms. of 30% acetic acid, warming if necessary and dilute with water to 50ml. (soln.A) In a separate vessel, stir 30gms. of zinc acetate with 3gms.of 30% acetic acid and dilute with water to 50ml. (soln.B) Mix the two solutions A and b, and add a small quantity of sodium chloride. Allow to stand for 24 hrs. and filter from the precipitated sodium zinc uranyl acetate.
Alternatively, a reagent of equivalent concentration may be prepared by dissolving uranyl zinc acetate in the appropriate volume of water or 1M acetic acid
Zwikkers reagent
Mix 1 ml of pyridine with 4 ml of a 10% aqueous solution of copper sulphate and 5 ml of water.

Signature: Dhanlal De Lloyd, Chem. Dept, The University of The West Indies, St. Augustine campus
The Republic of Trinidad and Tobago.
Copyright: delloyd2000© All rights reserved.