Question

(c) arrange the following compounds in order of increasing boiling point: cs₂, nah, co₂. 2 marks

Explanation:

Step1: Identify intermolecular forces

$CO_2$ is a non - polar molecule with only London dispersion forces. $CS_2$ is also a non - polar molecule with London dispersion forces. But $CS_2$ has a larger molar mass than $CO_2$, so it has stronger London dispersion forces. $NaH$ is an ionic compound with strong ionic bonds.

Step2: Compare boiling points

Ionic compounds have much higher boiling points than molecular compounds with only London dispersion forces. Among molecular compounds, the one with stronger London dispersion forces has a higher boiling point. So, the order of increasing boiling point is based on the strength of intermolecular forces.

Answer:

$CO_2