a simple hwk question.. i don't understand what i need to do..

1-butanol (shown below) burns in the presence of oxygen to give off carbon dioxide and water by the following reaction:
C4H9OH + 6 O2 ==> 4 CO2 + 5 H2O
If 40.88 mL of 1-butanol burns completely, how many grams of 1-butanol have burned? grams
(Hint: The density of 1-butanol is 0.810 g/mL)

1 answer