In which of the following conditions distance between molecules of carbon dioxide filled in a container may increase? (i) On increasing the volume of container (ii) On leakage of some carbon dioxide gas from the container (iii) On increasing air pressure in the container (iv) On adding more carbon dioxide gas in container without changing its size

The distance between molecules of a gas in a container is related to the volume the gas occupies and the number of molecules. (i) On increasing the volume of the container while the amount of gas remains the same, the molecules have more space, increasing the average distance between them. (ii) On leakage of some gas, the number of molecules decreases while the volume remains the same, leading to an increase in the average distance between the remaining molecules. (iii) Increasing air pressure in the container (assuming by adding air, not compressing the CO2) in a fixed volume increases the total number of molecules, thus decreasing the average distance between all molecules, including CO2. If interpreted as compressing the CO2, the volume decreases, decreasing distance. (iv) Adding more CO2 gas to a container of fixed size increases the number of molecules in the same volume, decreasing the average distance. Therefore, only conditions (i) and (ii) would increase the distance between CO2 molecules.