Question

Assertion: The electron gain enthalpy of $N$ is +ve while that of $P$ is -ve.

Reason: This is due to the smaller atomic size of N in which there is a considerable electron-electron repulsion and hence the additional electron is not accepted easily.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Both Assertion and Reason are incorrect

Answer 1

The correct option is A Both Assertion and Reason are correct and Reason is the correct explanation for Assertion

The electron gain enthalpy $\left(\text{in}kJmo{l}^{-1}\right)$ of phosphorus is negative while that of nitrogen is positive.
This is because, adding an electron in nitrogen cause high electron-electron repulsion due to the smaller size of nitrogen whereas in phosphorus the electron repulsion is less compared to nitrogen due to its larger size.
Thus, both assertion and reason are correct and reason is the correct explanation for assertion.
Hence, option (a) is correct.