Question

In $X-H...Y,$ both $X$ and $Y$ are electronegative elements. Then:

• A. The electron density on $X$ will increase and on $H$ it will decrease
• B. In both the elements, the electron density will increase
• C. In both the elements, the electron density will decrease
• D. On $X$ the electron density will decrease and on $H$ it will increase

Answer 1

The correct option is A The electron density on $X$ will increase and on $H$ it will decrease

In $X-H....Y$,
${}^{\prime }{H}^{\prime }$ is directly bonded to ${}^{\prime }{X}^{\prime }$ and there is an interaction between ${}^{\prime }{H}^{\prime }$ and ${}^{\prime }{Y}^{\prime }$. ${}^{\prime }{X}^{\prime }$ and ${}^{\prime }{Y}^{\prime }$ are both electronegative elements. Since ${}^{\prime }{X}^{\prime }$ is directly bonded to ${}^{\prime }{H}^{\prime }$, it pulls the shared electron cloud. So, the electron density on $X$ increases and on ${}^{\prime }{H}^{\prime }$, the electron density decreases.