Question

Among $H_{2}O,H_{2}S,H_{2}Se$ and $H_{2}Te$, the one with the highest boiling point is:

• A. $H_{2}O$ because of $H-$ bonding
• B. $H_{2}Te$ because of higher molecular weight
• C. $H_{2}S$ because of H - bonding
• D. $H_{2}Se$ because of lower molecular weight

Answer 1

The correct option is A $H_{2}O$ because of $H-$ bonding

Boiling point decreases down the group as the molar mass of the compounds increases.
But the order of boiling point is $H_{2}S<H_{2}Se<H_{2}Te<H_{2}O$ due to hydrogen bonding in water. So, water will have the stronger intermolecular force and hence, more temperature will be required to boil it.