when we boil a glass of water in a microwave and then put some capsules it dissolves slowly whereas when we put the capsules in the glass and then heat it it dissolves readily. WHY?Please elaborate the answer?

Dear student,

This is becoz

Solubility decreases with temperature..

The solubility of solutes is dependent on temperature. When a solid dissolves in a liquid, a change in the physical state of the solid analogous to melting takes place. Heat is required to break the bonds holding the molecules in the solid together. At the same time, heat is given off during the formation of new solute -- solvent bonds.

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Askiitians Expert

Sagar Singh

B.Tech, IIT Delhi

sagarsingh24.iitd@gmail.com

When we boil a glass of water in a microwave and then dissolve capsule in it then the capsule dissolves at a faster rate because the molecules of capsule on entering the water absorb heat due to which they get excited  try to break the intermolecular force of attraction between them and thus dissolve at a fast rate. There is some role of the water molecules also in disoolving the capsule. Water helps to break the force of attraction existing among the molecules. But when the temperature of water is normal then the molecules of the capsule do not get excited and thus only the molecules of water help to break the bond between them so they dissolve at a slow rate