If one benzene molecule is placed in water, the total entropy of the water + benzene system: a) is unchanged
b) it depends on the angle between the benzene carbon atoms
c) decreases
d) increases

d) increases

Explanation:

Benzene is an aromatic hydrocarbon which is obtained from the destructive distillation of coal. It is a colourless volatile liquid with a sweet smell. It boils ar 80° C (353 K) and freezes at 5°C (2278 K). It is insoluble in water but mixes in all proportions with ethanol, ethoxyethane and methylbenzene. The reason which benzene is insoluble in water is that benzene is a non-polar compound and water is polar, meanwhile only "like dissolves like". So, when the benzene molecule is placed in water. There will be distortion and disturbance between the benzene molecule and the water. Thus, the particle of each molecule will be distant from each other. This state results to change in the entropy of the system as the entropy of the system increases.

hydrocarbons are organic compounds that contain only hydrogens and carbons. they can be saturated (those which contain only carbon-carbon single bonds) or unsaturated (those which contain carbon-carbon double or triple bonds) in nature. hydrocarbons can undergo several reactions like substitution, elimination etc.  

on substituting one or more hydrogen atoms in hydrocarbon it results in the formation of haloalkane. as the halogen atoms are large compared to the carbon and hydrogen atoms, due to which the molecular weight increases and the bond become polar because of presence electronegative halogen atom and results in the increase in boiling point of the haloalkane.

thus, the correct option is (b) that is the boiling point of the new compound increases on substituting a hydrogen atom with a halogen in a hydrocarbon.