Part 3: Calculate the theoretical yield using stoichiometry. Then, use the theoretical yield to determine your percent yield. Use the balanced equation
below for your calculations.
1 N2 + 3 H2 → 2 NH3
1. How many grams of NH3 would be produced if 97 grams of N2were
reacted with an excess of H2?

"record the time to complete a chemical reaction" would most likely be part of a lab procedure.

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.