You are asked to make 12 moles of iron(Fe) from iron oxide and carbon monoxide. Fe2O3(s) + 3CO(g)→2Fe(l) + 3CO2(g)

Approximately how many moles of iron oxide(Fe2O3) is used?

From the equation we can see that

Moles of Fe=12

Moles of Fe_2O_3:-

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.