A sample of a substance containing only C and H burns in excess O2 to yield 4.4g of CO2
and 2.7 g of H2O. The empirical formula of a substance is?

(C = 12, O = 16, H = 1)

A.

CH3

B.

CH2

C.

CH4

D.

C2H24

Correct answer is A

CxHy + (x + y/4)O2 = XCO2 + (y/2)H2O
4.4 2.7
according to the equation 44x = 9y
Carbon Hydrogen
mole given ratio = (44)/(44), (2.7)/(9) = 0.1,0.3
Empirical formula = (0.1)/(0.1), (0.3)/(o.1) = 1,3 ; CH3