Question

An unknown compound contains only C, H, and O. Combustion of 3.10 g of this compound produced 7.05 g of CO2 and 2.88 g of H2O.

Answer 1

moles of CO2 = 7.05 / 44 = 0.1602

moles of C= 0.1602

mass of Carbon = 12 x 0.1602 = 1.9227 g

moles of H2O = 2.88 / 18 = 0.16

moles of H = 2 x 0.16 = 0.32

mass of hydroegen = 0.32 g

Oxygen mass = 3.10 - ( 1.9227+ 0.32 ) = 0.8573g

moles of O = 0.8573 /16 = 0.05358

C                O               H

0.1602     0.05358        0.32

3             1                    6

empirical formula formula of unknown = C3H6O