Why is iron added to sulfuric acid until there is some iron left over when you are making iron sulfate?

the answer is b. dilution

fe 55.85 g/mol and h2o 18.02 g/mol.

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.