A250 gram sample of water at the boiling point had 45.0 kj of heat added. how many grams of water were vaporized? heat of vaporization for water is 40.6 kj/mole.

the correct answer is:

a. formation of precipitation

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.