Question

Of the given hydrides of group 16 Elements, which is the most stable thermodynamically?

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

Answer 1

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

As we go down the group, the electronegativity of the central atom decreases while the atomic size increases. This causes the $E-H$ bond to weaken as we go down the group. Hence the thermal stability order is as $H_{2}O>H_{2}S>H_{2}Se>H_{2}Te>H_{2}Po$