Which of the following statements is true? A. The rate of all chemical reactions doubles for every 10 oC increase in temperature. B. Decreasing the activation energy of a reaction decreases the reaction rate. C. Catalysts increase the reaction rate without getting used up in the reaction. D. All of the Above E. None of the Above

i would say b

explanation:

but i think i would need more information than that

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.