Question

**** Chemistry Help in Exchange for Medal *****
A compound with a molecular mass of 56.104 grams is found to be 86% carbon. The rest of the compound is hydrogen. Find its molecular formula.
Select one:
a. C2H4
b. C4H8
c. C3H6
d. C6H10

I'm unsure how you find the molecular formula when given mass. Can someone help walk me through the process?

Answer 1

0.86 x 56.104 g = 48.25 g C

48.25 g C / 12.01 g C = 4

56.104 g – 48.25 g C = 7.75 g H = 8 g H

Answer is (B)

Answer 2

Thank you @bradyl2525. I appreciate the help. Is 12.01 just the atomic mass of one of the variables?