Suppose you wanted to know how many grams of KCl would be left if 350mL of a 2.0M KCl solution were evaporated to dryness.
b. How would heating the solution affect the mass of KCl?

52.2g of KCl would be left

The mass of KCl will remain despite the solution is been heated

Explanation:

When you are heating a solution, just the solvent (In this case, water), will be evaporated and, in theory, the mass of KCl will remain despite the solution is been heated.

Now, the mass of KCl that you can obtain from 350mL of a 2.0M solution will be:

Moles KCl:

350mL = 0.350L * (2.0mol / L) = 0.700 moles

Mass KCl -Molar mass: 74.55g/mol-:

0.700mol * (74.55g/mol) = 52.2g of KCl would be left

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.