Chemistry
Give reasons for the following:
Aqueous solution of lead and zinc nitrate can be distinguished using an aqueous solution of ammonia.
Answer
A lead salt gives a chalky white ppt. on reaction with ammonium hydroxide which does not dissolve when excess of ammonium hydroxide is added.
Pb(NO3)2 + 2NH4OH ⟶ 2NH4NO3 + Pb(OH)2 ↓
On the other hand, zinc salt forms a white gelatinous ppt. which dissolves when excess of ammonium hydroxide is added. Hence, the two can be easily distinguished using an aqueous solution of ammonia.
Related Questions
Give reasons for the following:
Finely divided iron catalyst does not affect the percentage yield of ammonia in Haber’s process.
Give reasons for the following:
Ammonium salts are formed when ammonia reacts with dilute acids in the gaseous or aq. medium.
Complete the statements by selecting the correct word from the words in brackets.
- The salt solution which does not give an insoluble precipitate on addition of ammonium hydroxide in small amount is ………….. [Mg(NO3)2/NaNO3/Cu(NO3)2]
- The alkaline behaviour of liquor ammonia is due to the presence of ………….. ions, [ammonium/hydronium/hydroxyl]
- Ammonia in the liquefied form is ………….. [acidic/basic/ neutral]
- Ammonia reduces chlorine to ………….. [nitrogen/hydrogen chloride/ ammonium chloride]
- The chemical not responsible for ozone depletion is ………….. [methyl chloride / ammonia / chloroflourocarbons]
Select the most probable substance from A, B, C, D and E which need to be added to distinguish :
Column A Column B 1. Ammonium sulphate and ammonium chloride A. Conc. hydrochloric acid 2. Potassium sulphate and ammonium sulphate B. Ammonia gas 3. Liquor ammonia and liquid ammonia C. Barium chloride 4. Ammonia and sulphur dioxide gas D. Phenolphthalein 5. Copper [II] oxide and copper [II] chloride E. Sodium hydroxide