Select the true statement about oxidation and reduction in an electrolytic cell.
a) both oxidation and reduction occur at the anode.
b) both oxidation and reduction occur at the cathode.
c) oxidation occurs at the anode and reduction occurs at the cathode.
d) oxidation occurs at the cathode and reduction occurs at the anode.

substituting a hydrogen atom with a halogen in a hydrocarbon:

- the single bond remains single. a is wrong.

- the bond with hydrogen is as strong as with a halogen. c is wrong

- a hydrocarbon is saturated if there is no double bond. we do not know that so d is wrong.

- carbon will always have four valence electrons. e is wrong.

by elimination, the correct answer is b. the boiling point of the new compound increases.