Question

Among the hydrides of group $16$ elements, which has the lowest boiling point?

Answer 1

The boiling points of the hydrides of group 16 elements is as follows:

• $H_{2}O$ $\to$ ${100}^{\circ }C$
• $H_{2}S$ $\to$ $-\left({60}^{\circ }C\right)$
• $H_{2}Se$ $\to$ $-\left({41.25}^{\circ }C\right)$
• $H_{2}Te$ $\to$ $-\left({2.2}^{\circ }C\right)$

• Gradual increase in boiling points down the rest of the group happens as the relative molecular mass of the molecules increases.
• Also, boiling point of water is $\text{anomalously}$ high.

Hence $H_{2}S$ has lowest boiling point here.