Question

Which one of the following is non-reducing?

• A. $H_{2}S$
• B. $H_{2}Te$
• C. $H_{2}Se$
• D. $H_{2}O$

Answer 1

The correct option is D $H_{2}O$

As the size of central metal atoms increases, $H-X-H$ (here, $X=O,S,Se,Te)$ bond strength decreases and thus, the reducing power increases. The order of reducing power is $H_{2}O<H_{2}S<H_{2}Se<H_{2}Te.$

Hence, $H_{2}O$ is non-reducing among the VI group hydrides.