Question

Take a dish and put some sodium nitrate and keep it exposed to air for 5-10 minutes. Observe the changes, write your observation. Sodium nitrate becomes white. Potassium nitrate does not become wet when exposed to air. Can you give reason for this?

Answer 1

• Sodium nitrate is a deliquescent solid, i.e., it absorbs moisture readily.
• Hence, if it is exposed to air, which has a considerable amount of water vapour present in it, sodium nitrate tends to become wet.
• On the other hand, potassium nitrate is not hygroscopic in nature. Hence, it does not get wet when exposed to air.