Sulphur pieces does not react with the cold concentrated nitric acid. But sulphur powder reacts.
a) Explain the reason why the rate of chemical reaction is increased here?
b) Suppose you want to increase the rate of reaction again. Which way would you choose? Gice reason.

Explanation

a) When sulphur is powdered, surface area increases. As a result the number of molecules undergoing effective collision also increases as per collision theory.
b) Increaeses the temperature. When the temperature increases the number of molecules with threshold energy increases. As a result the number effective collision increases and the thus the rate of reaction also.