Major product '$$\mathrm{P}$$' formed in the following reaction is:

Which of the following have same number of significant figures?

A. 0.00253

B. 1.0003

C. 15.0

D. 163

Choose the correct answer from the options given below

A compound '$$\mathrm{X}$$' when treated with phthalic anhydride in presence of concentrated $$\mathrm{H}_{2} \mathrm{SO}_{4}$$ yields '$$\mathrm{Y}$$'. '$$\mathrm{Y}$$' is used as an acid/base indicator. '$$\mathrm{X}$$' and '$$\mathrm{Y}$$' are respectively

Arrange the following gases in increasing order of van der Waals constant 'a'

A. Ar

B. $$\mathrm{CH}_{4}$$

C. $$\mathrm{H}_{2} \mathrm{O}$$

D. $$\mathrm{C}_{6} \mathrm{H}_{6}$$

Choose the correct option from the following.