Iv'e got a long one question one which of these is a chemical property of a substance? a. reactivity b. color c. boiling point d. melting point question two which of these is true of a chemical reaction? a. energy is always released b. energy is always obtained c. energy is either released or absorbed d. energy is not transferred question three which of these is an example of a chemical change? a. leaving cheese out to get moldy (this one prob) b. smelling sprayed perfume c. feeling ice melt on your skin d. crushing ice /w hammer question four which of these is an example of a chemical change? a. exploding fireworks b. grinding powder c. melting cheese d. ironing a shirt question five which of these is an example of a chemical change? a. cutting bread b. spreading peanut butter c. digesting a sandwich (prob this one) d. stirring jelly

1.) A

2.) C

3.) A

4.) A

5.) C

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.