EXERCISE XLII 



THE STUDY OF AMMONIACAL SOLUTION OF 

 COPPER CARBONATE 



Material. Copper sulphate, carbonate of soda, ammonia. 

 Apparatus. Quart glass jar, stirring-rod, granite kettle. 

 To make this fungicide it is necessary first to make the copper 

 carbonate. The common formula for copper carbonate is 



Copper sulphate . . . . . . . . ; . . 10 Ib. 



Water ............... 10 gal. 



Carbonate of soda 12 Ib. 



Water . . . . . . . . . , ,-, ... 10 gal. 



Laboratory formula. Weigh out two ounces of copper sulphate 

 and dissolve in one pint of water, and in a separate vessel 

 dissolve two ounces of carbonate of soda in one pint of water. 

 When cool, mix the two solutions slowly, stirring well. Allow 

 the solution to stand twelve hours to settle, after which pour off 

 the liquid. Add one quart of water and stir a second time, again 

 allowing the solution to stand for twelve hours. Repeat this 

 operation several times and then filter off the residue. The blue 

 powder thus obtained is copper carbonate. Describe fully the 

 operation and explain each step. What is the difference between 

 the finished product and the copper sulphate ? Write out the 

 chemical formula and give the resulting product. 



The common formula for ammoniacal solution of copper car- 

 bonate is 



Copper carbonate 6 oz. 



Ammonia 3 pt. 



Water , . . . . .... 50 gal. 



Laboratory formula. Weigh out one fourth of an ounce of 

 the copper carbonate just prepared and dissolve this in one eighth 

 of a pint of ammonia. When thoroughly dissolved, add enough 

 water to make two gallons. What is the function of the am- 

 monia ? Where is this fungicide used ? How does it differ in 

 this respect from Bordeaux mixture ? Give the chemical formula 

 of copper carbonate when mixed with the ammonia. 



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