Question

Assertion A: The dihedral angles in $H _{2} O _{2}$ in gaseous phase is $90.2^{\circ}$ and in solid phase is $111.5^{\circ}$.
Reason $R$ : The change in dihedral angle in solid and gaseous phase is due to the difference in the intermolecular forces.
Choose the most appropriate answer from the options given below for $A$ and $R$.

• A. $A$ is correct but $R$ is not correct.
• B. Both $A$ and $R$ are correct but $R$ is not the correct explanation of $A$.
• C. Both $A$ and $R$ are correct and $R$ is the correct explanation of $A$.
• D. A is not correct but $R$ is correct.

Answer 1

Answer: (D)

(a) $H _{2} O _{2}$ structure in gas phase, dihedral angle is $111.5^{\circ}$.
(b) $H _{2} O _{2}$ structure in solid phase at $110 \,K$, dihedral angle is $90.2^{\circ}$.
Hence given statement (A) is not correct But statement (B) is correct.