Question

How many milliliters of C5H12 are needed to make 97.3 ml C5H8?

density of C5H12 = 0.620 g/mL
density of C5H8 = 0.681 g/mL
density of H2= 0.0899g/L

Please explain

Answer 1

First of all, we can write a chemical equation.


`C _(5)H_(12) = C _(5)H_(8) + 2H_(2)`

Thus, we must use 1 mole C₅H₁₂ to obtain 1 mole C₅H₈ and 2 moles of hydrogen gas. According to conservation of mass law, products and reactants must have the same total mass.

97.3 ml C₅H₈= (97.3).(0.681)=66.26 gr. Moreover we can calculate its mole with molecular weight; C₅H₈=68 g/mole
Mole of C₅H₈=66.26/68=0.97
Mole of H₂= 1.94 Mass=1,94.2=3.89g Volume=3.89/0.0899=43.35 ml
Mole of C₅H₁₂=0.97 Mass=69.84 Volume=69.84/0.620=112.64 ml