Given below are two statements :

Statement I : Nitration of benzene involves the following step -

Statement II : Use of Lewis base promotes the electrophilic substitution of benzene.

In the light of the above statements, choose the most appropriate answer from the options given below :

Which of the following gives a positive test with ninhydrin ?

Given below are two statements: One is labelled as Assertion (A) and the other is labelled as Reason (R)

Assertion (A) : Enthalpy of neutralisation of strong monobasic acid with strong monoacidic base is always $$-57 \mathrm{~kJ} \mathrm{~mol}^{-1}$$

Reason (R) : Enthalpy of neutralisation is the amount of heat liberated when one mole of $$\mathrm{H}^{+}$$ ions furnished by acid combine with one mole of $${ }^{-} \mathrm{OH}$$ ions furnished by base to form one mole of water.

In the light of the above statements, choose the correct answer from the options given below.

Given below are two statements:

Statement I: In group 13, the stability of +1 oxidation state increases down the group.

Statement II : The atomic size of gallium is greater than that of aluminium.

In the light of the above statements, choose the most appropriate answer from the options given below :