State the colour of :

1. Phenolphthalein solution after passage of ammonia through it.
2. Copper (II) hydroxide solution after addition of ammonium hydroxide in excess to it.
3. The flame obtained on burning dry ammonia in oxygen.
4. The solution obtained on addition of excess ammonium hydroxide to zinc sulphate solution.
5. The vapours obtained when ammonia-oxygen gas mixture is passed over heated Pt.

Give reasons for the following:

A mixture of ammonium nitrate and slaked lime are not used in the lab. preparation of ammonia gas.

Give reasons for the following:

Finely divided iron catalyst does not affect the percentage yield of ammonia in Haber’s process.