Question

Boiling point is a function of molecular mass and interparticle bonding. What would be the order of extraction, from first to last, for a mixture of substances in a distillation based on the following compounds: water, dihydrogen sulfide, dihydrogen selenide, dihydrogen telluride?

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

Answer 1

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

The melting and boiling points increase down the group because of the van der Waals forces. The size of the molecules increases down the group. This increase in size means an increase in the strength of the van der Waals forces

so the distillation is opposite to the boiling point to the periodic table

$H_{2}Te,H_{2}Se,H_{2}S,H_{2}O$