Answer the following question :
How will you distinguish between Ammonium hydroxide and Sodium hydroxide using copper sulphate solution?

Explanation

When ammonium hydroxide solution is added drop by drop to copper sulphate solution, a pale blue or bluish white precipitate is formed which is soluble in excess of ammonium hydroxide and a deep blue or inky blue solution is formed with excess of ammonium hydroxide.
`CuSO_4 + 2NH_4OH rarr Cu(OH)_2 darr + (NH_4)2SO_4`
`Cu(OH)_2 + 4NH_4OH rarr [Cu(NH_3)_4] (OH)_2 + 4H_2O`
Copper solution forms a blue precipitate with sodium hydroxide solution. It is insoluble in excess of NaOH.
`underset(underset("sulphate")("Copper"))(CuSO_4) + underset(underset("hydroxide")("Sodium"))(2NaOH) rarr underset(underset("hydroxide")("Copper"))(Cu(OH)_2) +underset(underset("sulphate")("Sodium"))(Na_2SO_4)`