Question

Rahul puts a few drops of alcohol on the back of his hand, the alcohol disappears and his hand feels cool. Why does this happen?

April 27, 2024

Answer

This happens because the heat energy required for the change is provided by the body.

💡 Some Related Questions

What kind of change is the formation of clouds?

Paheli mixed flour and water and (i) made a dough (ii) rolled the dough to make a chapati (iii) baked the chapati on a pan. (iv) dried the chapati and ground it in a grinder to make powder. Identify the changes (i) to (iv) as the changes that can be reversed or that cannot be reversed.

Change of a bud into a flower is a change which cannot be reversed. Give four more such examples.

Conversion of ice into water and water into ice is an example of change which can be reversed. Give four more examples where you can say that the changes can be reversed.

A potter working on his wheel shaped a lump of clay into a pot. He then baked the pot in an oven. Do these two acts lead to the same kind of changes or different? Give your opinion and justify your answer.

Give one example in each case. (i) Change which occurs on heating but can be reversed. (ii) Change which occurs on heating but cannot be reversed. (iii) Change which occurs on cooling but can be reversed. (iv) Change which occurs on mixing two substances, but can be reversed. (v) Change which occurs on mixing two substances, but cannot be reversed.

Explain the term ‘solute’ and ‘solvent’ with an example

‘Changes involve interaction.’ Give an example to support this statement.

Can a change take place when two materials are not in contact? Give an example to support your answer.

Energy is needed for a change. Give two examples to support this statement.