Question

Statement I Ammonia is a colourless gas with a pungent order. Statement II Its freezing and boiling points are $198.4$ and $239.7 \,K$ respectively.

• A. Statement $I$ and Statement $II$ are correct and Statement $II$ is the correct explanation of Statement $I$.
• B. Statement $ I$ and Statement II are correct but Statement II is not the correct explanation of Statement $I$.
• C. Statement $I$ is correct but Statement $II$ is incorrect.
• D. Statement $II$ is correct but Statement $I$ is incorrect.

Answer 1

Answer: (A)

Ammonia is a colourless gas with a pungent order. Its freezing and boiling points are $198.4$ and $239.7 \,K$ respectively. In the solid and liquid states, it is associated through $H$-bonds.
As in the case of water $H$-bonds are account for its higher melting and boiling points than expected on the basis of its molecular mass.