Neutral potassium chromate

Synonyms neutral potassium chromate potassium chromate(VI) tarapacaite... 

Synonym Neatsfoot Oil Necatorina Nechexane Neutral Ahhonium Pluoride Neutral Anhydrous Calcium Hypochlorite Neutral Lead Acetate Neutral Nicotine Sulfate Neutral Potassium Chromate Neutral Sodium Chromatetanhydrous Neutral Verdigris Nickel Acetate Nickel Acetate Tetrahyorate Nickel Ammonium Sulfate Nickel Ammonium Sulfate Hexahydrate Nickel Bromide Nickel Bromide Trihydrate Nickel Carbonyl Nickel Chloride Nickel Chloride Nickel Cyanide Nickel Iiu Fluoborate Nickel Fluoroborate Solution Nickel Fluoroborate Nickel Formate Nickel Formate Dihyorate Nickel Nitrate Nickel Nitrate Hexahydrate Nickel Sulfate Nickel Tetracarbokyl Nickelous Acetate Nickelous Sulfate Nicotine Nicotine Sulfate Nifos Nitralin Nitram O-Nitraniline P-Nitraniline Nitric Acid Nitric Acid, Aluminum Salt Nitric Acid, Iron (111) Salt Compound Name Oil Neatsfoot Carbon Tetrachloride Neohexane Ammonium Fluoride Calcium Hypochlorite Lead Acetate Nicotine Sulfate Potassium Chromate Sodium Chromate Copper Acetate Nickel Acetate Nickel Acetate Nickel Ammonium Sulfate Nickel Ammonium Sulfate Nickel Bromide Nickel Bromide Nickel Carbonyl Nickel Chloride Nickel Chloride Nickel Cyanide Nickel Fluoroborate Nickel Fluoroborate Nickel Fluoroborate Nickel Formate Nickel Formate Nickel Nitrate Nickel Nitrate Nickel Sulfate Nickel Carbonyl Nickel Acetate Nickel Sulfate Nicotine Nicotine Sulfate Tetraethyl Pyrophosphate Nitralin Ammonium Nitrate 2-Nitroaniline 4-Nitroaniline Nitric Acid Aluminum Nitrate Ferric Nitrate... 

SYNS BIPOTASSIUM chromate CHROMATE OF POTASSIUM DIPOTASSIUM CHROMATE DIPOTASSIUM MONOCHROMATE NEUTRAL POTASSIUM CHROMATE TARAPACAITE... 

Chromic Oxide—Sesquioiide or green oxide of cArowiMm—Cr,0,— 152.8—obtained, amorphous, by calcining a mixture of potassium dichromate and starch, or, crystallized, by heating neutral potassium chromate to redness in Cl. 

Quantitative determination of chlorids in urine.—The process is based upon the formation of the insoluble silver chlorid, and upon the formation of the brown silver chroiiiate in neutral liquids, in the absence of soluble chTorids. The solutions required are (1) A solution of silver nitrate of known strength, made by dissolving 29.075 grams of pure, fused silver nitrate (see p. 193) in a litre of water (3) a solution of neutral potassium chromate. 

Neutral-lactase. See p-Galactosidase Neutral potassium chromate. See Potassium... 

Synonyms Bipotassium chromate Chromate of potass Chromate of potassium Chromic acid, dipotassium salt Dipotassium chromate Dipotassium monochromate Neutral potassium chromate Potassium chromate (VI) Potassium chromate, yellow Tarapacaite Empirical CrK204 Formula K2Cr04... 

Actual Chloride, either titrated with N/10 silver nitrate solution, using neutral potassium chromate solution as indicator, or, preferably, estimated gravimetrically as silver chloride by precipitation with silver nitrate solution, the precipitate transferred to a tared filter paper, washed, dried and weighed. 

Neutral Ahhonium Pluoride Neutral Anhydrous Calcium Hypochlcrite Neutral Lead Acetate Neutral Nicotine Sulfate Neutral Potassium Chromate Neutral Sodium Chromatetanhydrous Neutral Verdigris Nickel Acetate... 

Synonyms Neutral potassium chromate Potassium chromate (VI) Chemical Formula KjCiO (ii) Observable Characteristics — Physical State (as shipped) Solid Color Bright yellow Odor None (Hi) Physical and Chemical Properties — Physical State at 15 X and I atm. Solid Molecular Weight 194,20 Boiling Point at I atm. Not pertinent (decomposes) Freezing... 

In neutral solution, the indicator is potassium chromate(VI). In acid solution the CrOj" ion changes to CrjO (p. 378). and since silver dichromatefVI) is soluble, chromate(VI) is not a suitable indicator other methods can be used under these conditions. (In alkaline solution, silverfl) oxide precipitates, so silver(I) nitrate cannot be used under these conditions.)... 

Potassium chromate(VI) gives a brick-red precipitate of silver chromate(VI) in neutral solution. 

Discussion. Very pure silver can be obtained commercially, and a standard solution can be prepared by dissolving a known weight (say, 10.787 g) in nitric acid in a conical flask having a funnel in the neck to prevent mechanical loss, and making up to a known volume (say, 1 L for a 0.1 M solution). The presence of acid must, however, be avoided in determinations with potassium chromate as indicator or in determinations employing adsorption indicators. It is therefore preferable to employ a neutral solution prepared by dissolving silver nitrate (relative molecular mass, 169.87) in water. 

Procedure Weigh accurately about 4 g of chloral hydrate and dissolve in 10 ml of DW and add 30 ml of N sodium hydroxide solution. Allow the resulting mixture to stand for 2 minutes, and then titrate with N sulphuric acid, employing phenolphthalein solution as indicator till a colour change from pink to colourless is achieved. Titrate the neutralized liquid thus obtained with 0.1 N silver nitrate using potassium chromate solution as indicator till precipitation of red chromate is obtained, Add, now 2/15th of the amount of 0.1 N silver nitrate used to the amount of N sulphuric acid used in the first titration and deduct the figure so obtained... 

Lead chromate is found naturally in minerals crocoite and phoenicochroite. It also is readily prepared by adding a soluble chromate such as sodium or potassium chromate to a solution of lead nitrate, lead acetate or other soluble lead(II) salt in neutral or slightly acidic solution ... 

Chlorides, bromides, and iodides can be quantitatively determined by treatment with silver nitrate, and, with suitable precautions, the precipitated halide is washed, dried, and weighed. Chlorides in neutral soln. can be determined by F. Mohr s volumetric process 27 by titration with a standard soln. of silver nitrate with a little potassium chromate or sodium phosphate as indicator. When all the chloride has reacted with the silver nitrate, any further addition of this salt gives a yellow coloration with the phosphate, and a red coloration with the chromate. In J. Volhard s volumetric process, the chloride is treated with an excess of an acidified soln. of silver nitrate of known concentration. The excess of silver nitrate is filtered from the precipitated chloride, and titrated with a standard soln. of ammonium thiocyanate, NH4CN8—a little ferric alum is used as indicator. When the silver nitrate is all converted into thiocyanate AgN03-fNH4CNS=AgCNS +NH4NOS, the blood-red coloration of ferric thiocyanate appears. 

Neutral solutions of cobalt salts produce with potassium chromate a reddish brown precipitate of hydrated basic cobalt chromate, Co0.CoGrO4.Aq. This reaction may be utilised in detecting small quantities of cobalt.4... 

Sodium Chloride Dissolve about 5 g of sample, accurately weighed, in about 50 mL of water. Neutralize the solution with 1 20 nitric acid, using litmus paper as the indicator add 2 mL of potassium chromate TS and titrate with 0.1 A silver nitrate. Each milliliter of 0.1 A silver nitrate is equivalent to 5.844 mg of sodium chloride (NaCl). 

Potassium chromate in neutral, acetic acid or ammonia solution yellow precipitate of lead chromate... 

Potassium chromate in neutral solution red precipitate of silver chromate... 

Volumetric estimation4 in neutral solution can be effected by titration with standard sodium chloride, potassium chromate being employed as indicator and in nitric-acid solution with thiocyanate, using ferric alum as indicator, or with sodium chloride without any external indicator. 

The presence of an indicator is not essential, since when neutral the colour changes from reddish yellow to greenish yellow. Potassium chromate is estimated by titration with sulphuric acid, Congo red being used as the indicator ... 

Titrate 20 ml aliquots with 0.1 N NaOH using phenolphthalein indicator, then titrate the neutralized solution with 0.1 N AgNOj using potassium chromate indicator. 

Potassium chromate 4 186 K2 4 Chromate of potassa monochromate of potassa neutral chromate of potassa potasJtc chromate salt of chrome yellow chromate of potassa. 

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