Question
Critical temperature for carbon dioxide (CO2) and methane (CH4) are 31·1°C and –81 ·9°C respectively. Which of these has stronger intermolecular forces and why?
Solution
We know that higher the critical temperature, more easily the gas can be liquefied i.e. greater are intermolecular forces of attraction. This means that the intermolecular forces of attraction between the molecules of a gas are directly proportional to its critical temperature. Since CO2 has greater critical temperature than CH4, therefore CO2 has stronger intermolecular forces than CH4.
