Give a chemical test to distinguish between the following pairs of compounds :
Calcium nitrate solution and zinc nitrate solution.

Explanation

Calcium nitrate and Zinc nitrate solutions can be distinguish by reacting with ammonium hydroxide solution :
(a) adding ammonium hydroxide gelatinous white precipitates of zinc hydroxide are formed.
`Zn(NO_(3))_(2)+2NH_(4)OH to Zn(OH)_(2)+2NH_(4)NO_(3)`
(b) On adding excess of ammonium hydroxide, the precipitates dissolve forming a soluble complex.
`Zn(NO)_(2)+2NH_(4)NO_(3) to 2NH_(4)OH to [Zn(NH_(3))_(4)](NO_(3))_(2)+4H_(2)O`
No visible reaction occurs when we add calcium nitrate to ammonium hydroxide.
`CaNO_(3)+NH_(4)OH to "No reaction"`