Question

a compound contain 92.4 percent and 7.6 percent H .its molecular mass is 78. what is its empirical and molecular formula?

Answer 1

The molecular mass of an organic compound is 78 and its percentage combination is 92.4% and 7.6%. What is the empirical formula and molecular formula of the compound?

Assuming it is a hydrocarbon.

carbon= 92.4 grams and hydrogen= 7.6 grams.

Moles of carbon= 92.4/12= 7.7 moles

Moles of Hydrogen= 7.6/1= 7.6 moles

Finding the simple ratios, C=7.7/7.6= 1 (approx) and H= 7.6/7.6= 1 .

Therefore empirical formula is CH.

n = molar mass/ molar mass of empirical formula

= 78/13

n = 6

Multiply ’n’ to empirical formula, Therefore molecular formula is C6H6 (benzene).

Hope this help !!