Solution

$$\text { In } \mathrm{H}_{2} 0 \text { , there are Hydrogen bonds } \\$$
$$\text { present because of Oxygen's small } \\$$
$$\text { size and high electronegativity. So as } \\$$
$$\text { it leads to Higher forces of attraction } \\$$
$$\text { and stronger bonds it is difficult to } \\$$
$$\text { break. therefore, } \mathrm{H}_{2} 0 \text { thas Higher boiling } \\$$
$$\text { pt than other hydrides of group } 16 \text { . }$$