What is the effect of shaking dilute $H_2SO_4$ with a small quantity of anhydrous $CuSO_4$?

$A$ substance used as a moderator in nuclear reactors is

Which of the following statements does not define the characteristic property of water,"Water is a universal solvent"?

The one that is $NOT$ suitable for the removal of permanent hardness of water is :

Given below are two statements:
Statement-$I$: Permutit process is more efficient compared to the synthetic resin method for the softening of water.
Statement-$II$: Synthetic resin method results in the formation of soluble sodium salts.
In the light of the above statements,choose the most appropriate answer from the options given below:

The hydride ion $H^{-}$ is a stronger base than the hydroxide ion $OH^{-}$. Which of the following reactions will occur if sodium hydride $(NaH)$ is dissolved in water?