Question

The oxygen family, also called the chalcogens, consists of the elements found in Group 16 of the periodic table and is considered among the main group elements.

Which of the following has lowest boiling point ?
[1 Mark]

• A. $H_{2}O$
• B. $H_{2}S$
• C. $H_{2}Se$
• D. $H_{2}Te$

Answer 1

The correct option is B $H_{2}S$

Boiling point is dependent on van der-wall forces of attraction which directly proportional to molar mass.

$H_{2}S$ has the lowest boiling point.

The correct order of boiling points is $H_{2}S<H_{2}Se<H_{2}Te<H_{2}O$
The boiling point of $H_{2}O$ is maximum due to to hydrogen bonding .
On moving down the group, the boiling point increases.