If pressure is constant, the volume of a gas as the temperature decreases.

The combined gas law is an equation that relates the pressure, temperature and volume of a gas. Based on this equation, you can predict what will happen to a sample of gas if you change one of the variables. If you decrease pressure and temperature simultaneously, you will not know the exact result unless you know the exact values by which each quantity decreased.

The combined gas law is an equation that relates the pressure, temperature and volume of a gas. Based on this equation, you can predict what will happen to a sample of gas if you change one of the variables. If you decrease pressure and temperature simultaneously, you will not know the exact result unless you know the exact values by which each quantity decreased.

it forms an anion that has a larger radius. anions have a negative charge and are larger than the original atom.

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.