APPENDIX 335 



solve the melt in water, add sulphuric acid. Note any changes 

 of color. 



EXP. 69. Dilute 1 cc. of stannous chloride in a beaker with 

 25 cc. of water; add 5 cc. of hydrochloric acid. Stir, and add 

 potassium permanganate solution drop by drop. What is taking 

 place ? 



IRON 



EXP. 70. Add ammonium hydroxide to ferrous sulphate solu- 

 tion. 



EXP. 71. Add ammonium hydroxide to ferric chloride solu- 

 tion. 



EXP. 72. Add 2 cc. dilute sulphuric acid to 5 cc. of ferrous 

 sulphate solution, then 10 drops of nitric acid, and heat. Observe 

 that the solution becomes almost black and suddenly clears, giving 

 off red fumes. Add a couple of drops of nitric acid and continue 

 doing this until no more red fumes appear. Cool and render alka- 

 line with ammonium hydroxide. 



EXP. 73. Add some hydrochloric acid and a little metallic iron 

 to 10 cc. of ferric chloride solution. As soon as this solution has 

 become colorless, filter into a fresh test-tube, and add ammonium 

 hydroxide. 



EXP. 74. Add stannous chloride to ferric chloride, until color- 

 less, and then make alkaline with potassium hydroxide. 



EXP. 75. Dilute a little ferrous sulphate in a beaker with 

 water, add a few drops of sulphuric acid, and then potassium per- 

 manganate, drop by drop. 



EXP. 76. Add potassium ferrocyanide to ferrous sulphate. 



EXP. 77. Add potassium ferrocyanide to ferric chloride. 



EXP. 78. Add potassium ferricyanide to ferrous sulphate. 



EXP. 79. Add potassium ferricyanide to ferric chloride. 



EXP. 80. Add potassium sulphocyanate to ferrous sulphate. 



EXP. 81. Add potassium sulphocyanate to ferric chloride. 



