Potassium-Copper Sulphate

Potassium-Copper Sulphate, K2S04- CuS04- 6H20 

Read the preliminary discussion which precedes the preparation of ammonium-copper sulphate, page 61. 

8-inch crystallizing dish, iron ring and ring stand. 

Procedure Prepare potassium-copper sulphate from potassium sulphate and copper sulphate. Follow the procedure outlined in the previous preparation. Determine the volume of water to be used to give a saturated solution at 25°. 

Water combined as water of hydration in crystals is in a true state of chemical combination, for the hydrated crystal shows the following characteristics of a chemical compound. 

---

Solubility of Mixed Crystals of Potassium Copper Sulphate AND Ammonium Copper Sulphate in Water. 

Fehling s solution A solution of copper sulphate, sodium potassium tartrate and NaOH used for estimating and detecting reducing sugars. 

Potassium cupro-cyanide is the most convenient form in which cuprous cyanide can be used in Sandmeyer s Reaction. It is prepared by adding an excess of potassium cyanide to copper sulphate solution, whereby the cupric cyanide which is formed immediately breaks down to give cuprous cyanide and cyanogen, and the cuprous cyanide then dissolves in the excess of potassium... 

Required Aniline, 20 ml. hydrochloric acid, 50 ml. sodium nitrite, 17 g. copper sulphate, 55 g. potassium cyanide, 60 g. 

Then, while the diazonium solution is standing in ice-water, dissolve 55 g. of powdered copper sulphate (CuS04,5Ha0) in 200 ml. of water contained in a 1500 ml. flat-bottomed flask, for which a steam-distillation fitting is available for subsequent use. Place a thermometer in the copper sulphate solution and warm the latter to 60-65 . Now cautiously add a solution of 60 g. of powdered potassium cyanide in too ml. of water to the copper... 

Benzonitrile (phenyl cyanide). Prepare a cuprous cyanide solution in a 500 ml. round-bottomed flask as above, but use the following quantities 65 g. of crystallised copper sulphate in 205 ml. of water, 18 g. of sodium bisulphite in 52 ml. of water, and 18 g. of potassium cyanide in... 

With potassium ferricyanide and sodium hydroxide solution ephedrine forms benzaldehyde. A solution of the hydrochloride gives with copper sulphate and sodium hydroxide solutions, a purple coloration extractable by ether, leaving the aqueous layer blue. A solution of ephedrine base in chloroform on standing is partially converted into ephedrine hydrochloride. ... 

Alternative procedure. The following method utilises a trace of copper sulphate as a catalyst to increase the speed of the reaction in consequence, a weaker acid (acetic acid) may be employed and the extent of atmospheric oxidation of hydriodic acid reduced. Place 25.0 mL of 0.017M potassium dichromate in a 250 mL conical flask, add 5.0 mL of glacial acetic acid, 5 mL of 0.001M copper sulphate, and wash the sides of the flask with distilled water. Add 30 mL of 10 per cent potassium iodide solution, and titrate the iodine as liberated with the approximately 0.1M thiosulphate solution, introducing a little starch indicator towards the end. The titration may be completed in 3-4 minutes after the addition of the potassium iodide solution. Subtract 0.05 mL to allow for the iodine liberated by the copper sulphate catalyst. 

Bartlett et al. [55] used the method of Uthe et al. [70] for determining methylmercury. Sediment samples of 2-5g were extracted with toluene after treatment with copper sulphate and an acidic solution of potassium bromide. Methylmercury was then back extracted into aqueous sodium thiosulphate. This was then treated with acidic potassium bromide and copper sulphate following which the methylmercury was extracted into pesticide grade... 

A solution of 55 g. of potassium cyanide in 100 c.c. of water is added gradually with continued warming to copper sulphate solution, prepared by heating 50 g. of the salt with 200 c.c. of water in a two-litre flask on the water bath. (Evolution of cyanogen Fume chamber )... 

Lactose is a reducing sugar, i.e. it is capable of reducing appropriate oxidizing agents, two of which are usually used, i.e. alkaline copper sulphate (CuS04 in sodium potassium tartrate Fehling s solution) or chloroamine-T (2.1). 

Hydrofluoric acid like water is an associated liquid, and even the gas, as we shall soon see, is associated. It has the power of uniting with fluorides. It also seems to be an ionizing solvent for a soln. of potassium fluoride in liquid hydrogen fluoride is an excellent conductor it also possesses marked solvent powers. According to E. C. Franklin,7 the liquid readily dissolves potassium fluoride, ehloride, and sulphate sodium fluoride, bromide, nitrate, chlorate, and bromate acetamide and urea. The solvent action is not so marked with barium fluoride, cupric chloride, and silver cyanide while calcium and lead fluorides copper sulphate and nitrate ferric chloride, mercuric oxide, and magnesium metal, are virtually insoluble in this menstruum. Glass also is not affected by the liquid if moisture be absent. The liquid scarcely acts on most of the metals or non-metals at ordinary temp., though it does act on the alkali metals at ordinary temp., much the same as does water, with the simultaneous production of flame. 

Put about 0.01 g of anhydrous copper sulphate and several crystals of potassium iodide into a dry porcelain mortar. Mix these substances with a pestle, and then triturate them. What do you observe Add a few drops of water to the mixture. Explain the observed phenomena. Write the equation of the reaction. 

Preparation of Purified Iodine. Dissolve 32 g of potassium iodide in 100 ml of water and 25 g of copper sulphate pentahydrate in 80 ml of water. Pour the solutions together into a 200-ml glass beaker and let the solution settle. Separate the precipitate from the... 

Burns produced by phosphorus are very dangerous If white phosphorus gets on your skin, immediately remove it and wash the burnt spot with a 2% silver nitrate, copper sulphate, or potassium permanganate solution. After carrying out experiments with white or red phosphorus, immerse the laboratory ware for some time in a 10% copper sulphate solution, after which wash it in the usual way. 

Pour a small amount of copper sulphate, silver nitrate, and potassium manganate solutions into three beakers and drop a small piece of white phosphorus into each of them. In 10 or 15 minutes, extract the phosphorus from the solutions. Dry it as indicated above, put it on an iron plate, and heat it. What happens How do the given salts affect white phosphorus How can the different activity of white and red phosphorus be explained Write the equations of [the [reactions. 

Copper(I) Iodide. Pour together equal volumes of 1 N copper sulphate and potassium iodide solutions. What is observed Pass a stream of sulphur dioxide through the mixture. How doe.s the colour of the solution change Write the equations of the reactions. 

---