Question

The increasing order of volatility of hydrides of the group $16$ elements is :

• A. $H_{2}S<H_{2}O<H_{2}Se<H_{2}Te$
• B. $H_{2}O<H_{2}Te<H_{2}Se<H_{2}S$
• C. $H_{2}O<H_{2}S<H_{2}Se<H_{2}Te$
• D. none of these

Answer 1

The correct option is B $H_{2}O<H_{2}Te<H_{2}Se<H_{2}S$

The volatility of the compounds depends on the molecular weight of the compound. More is the weight of the compound less volatility is the compound. So, volatility decreases down the group.

But $H_{2}O$ is an exception due to the presence of intermolecular H- Bond, which makes it least volatile.

So, the order of volatility is $H_{2}O<H_{2}Te<H_{2}Se<H_{2}S$.

So, the correct answer is option B.