Question

In the following question a statement of Assertion (A) followed by a statement of Reason (R) is given. Choose the correct option out of the choices given below.

Assertion (A):

Among the $O-H$ bonds in $H_{2}O$ molecule, the energy required to break the first

$O-H$ bond and the other

$O-H$ bond is the same.

Reason (R):

This is because the electronic environment around oxygen is the same even after breakage of one $O-H$ bond.

• A. A and R both are correct, and R is the correct explanation of A.
• B. A is true but R is false.
• C. A and R both are false.
• D. A and R both are correct, but R is not the correct explanation of A.

Answer 1

The correct option is C

A and R both are false.

Analysing assertion and reason:

Energy required to break the $O-H$ bond in the $H_{2}O$ molecule will not be the same for both $O-H$ bonds because the electronic environment of ${}^{-}O-H$ bond changed after breaking first $O-H$ bond in $H_{2}O$ molecule.

$H-O-H+E_1{\to }^{-}O-H+H^{+}$
$O-H+E_2\to O^{2-}+H^{+}$

$E_1\ne E_2$

Hence, the correct answer is option D.