Silver tarnishes when exposed to oxygen and dihydrogen mono sulfide, The chemical reaction is as follows: 4Ag(s) + 2H2S(g) + O2--->2Ag2S(s) + 2H2O(l) Every household has some H2S in the air (it smells like rotting eggs), but there is usually only a small quantity. H2S is almost always a limiting reaction, If a silver spoon has 0.0030 moles of tarnish on it, how many moles of H2S was it exposed to?

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.