Question

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

Assertion A : The dihedral angles in $H_2{O}_2$ in gaseous phase is 90.2° and in solid phase is 111.5°.
Reason R : The change in dihedral angle in solid and gaseous phase is due to the difference in the inter molecular 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

The correct option is D A is not correct but R is correct.

(a) $H_2{O}_2$ structure in gas phase, dihedral angle is 111.5°.
(b) $H_2{O}_2$ structure in solid phase at $110K$, dihedral angle is 90.2°.


The change in dihedral angle in solid and gaseous phase is due to the difference in the inter molecular forces.
Thus, assertion is wrong but statement R is correct.
Hence, option (d) is correct answer.