What do you observe when ammonium hydroxide is added to the aqueous solution of lead nitrate?

Distinguish between the following (using ammonia solution) :

Ammonium chloride and sodium chloride.

Distinguish between the following (using ammonia solution) :

Ferric salt and ferrous salt.

Distinguish between the following (using ammonia solution) :

Sodium sulphate and ammonium sulphate.

Give balanced equation for the following conversion,  

Ammonia to nitrogen using an acidic gas.

Give balanced equation for the following conversion,

Ammonia to brown gas.
 

Give balanced equation for the following conversion,

Ammonia to nitrogen trichioride.