Question

A sample of a compound contains 60.0 g C and 5.05 g H. It’s molar mass is 78.12 g/mol. What is the compound’s molecular formula?

Answer 1

Answer:

C6H6

Explanation:

C :     60.0 g*1 mol/12 .01g = 5.00 mol

H:      5.05 g * 1 mol/1.01 g= 5.10 mol

C:H = 5.00 mol : 5.10 mol = 1:1

CH is an empirical formula

Molar mass (12.01 +1.01)=13.02 g/mol

78.12g/mol /13.02 g/mol =6

Molecular formula is the empirical that was taken 6 times (CH)6 = C6H6