336 APPENDIX 



COPPER 



EXP. 8. Test the action of hydrochloric, nitric and hot sul- 

 phuric acids on copper, noting the fumes that are given off in each 

 case. 



f EXP. 83. Dilute 5 cc. of copper sulphate solution with an equal 

 quantity of water. Add small bits of iron and heat. What changes 

 take place? 



! EXP. 84. Add potassium hydroxide to copper sulphate solu- 

 tion until it is strongly alkaline. 



EXP. 85. Add ammonium hydroxide to copper sulphate drop 

 by drop, amid constant shaking, until the solution is alkaline. 



1 EXP. 86. Weigh out .4 gram of crystallized copper sulphate 

 (which contains about .1 gram of copper), and dissolve in 9.6 cc. 

 of water. Measure 1 cc. of this solution into a test-tube and mix 

 with 9 cc. of water. To a portion of this diluted solution add a few 

 drops of ammonium hydroxide; of the remainder, measure 1 cc. 

 into a fresh test-tube and mix with 9 cc. of water. Test a portion of 

 this more dilute mixture with ammonium hydroxide, and proceed 

 as before, always preparing a solution one-tenth as strong as the 

 preceding one, until a drop of ammonium hydroxide fails to pro- 

 duce a noticeable coloration. Calculate the amount of copper per 

 cubic centimeter that is required to give a visible reaction with 

 the ammonium hydroxide. 



EXP. 87. Add potassium ferrocyanide to dilute copper sul- 

 phate solution. 



EXP. 88. Weigh a crucible; add about two grams of crystallized 

 copper sulphate; weigh again. Heat carefully until the salt is quite 

 white; cool, and reweigh. How much water did the crystals contain? 

 Add a drop of water to the white residue. 



SILVER 



EXP. 89. Add hydrochloric acid, little by little, to 5 cc. of sil- 

 ver nitrate until no more precipitate is formed. Throw the pre- 

 cipitate upon a filter and wash. Then open out the filter and 



