First, let's go through what isomerism is. Isomerism is the relation of two or more compounds, radicals, or ions that are composed of the same kinds and numbers of atoms but differ from each other in structural arrangement (structural isomerism), as CH3OCH3 and CH3CH2OH, or in the arrangement of their atoms in space and therefore in one or more properties. There are 5 types of structural isomerism. They are chain isomerism, position isomerism, functional group isomerism, metamerism, and tautomerism. This would mean that these types of structural isomerism that are in the options would be eliminated as the question ask which of the "following" is not a type of structural isomerism. This would leave the only option available which is Option B. Optical Isomerism. So instead of being a structural isomerism, it is a type of stereoisomerism. Stereoisomerism is the arrangement of atoms in molecules whose connectivity remains the same but their arrangement in space is different in each isomer.
We are tasked to solve for the volume of the gas that occupies when pressure and temperature changes to 400 Torr and 200 Kelvin from Torr and 400 Kelvin. We can use ideal gas law assuming constant gas composition and close system. The solution is shown below: P1V1 / T1 = P2V2 / T2 V2 = P1V1T2 / T1P2 V2 = 800*72*200 / 400*400 V2 = 72 ml
