Solution

The boiling points of the hydrides of group 16 elements is as follows: $$H_2O$$ $$\rightarrow$$ $$100^{\circ}C$$ $$H_2S$$ $$\rightarrow$$ $$- (60^{\circ }C)$$ $$H_2Se$$ $$\rightarrow$$ $$-(41.25^{\circ}C)$$ $$H_2Te$$ $$\rightarrow$$ $$-(2.2^{\circ}C)$$ 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 $$\textbf{anomalously}$$ high. Hence $$H_2S$$ has lowest boiling point here.