Question

A compound has a molar mass of 58.0714 g. Further analysis has also revealed that the compound consists of 18 g of carbon, 3 g of hydrogen, and 8 g of oxygen.  What is the percent composition of all the components in the liquid and the empirical formula.

Answer 1

molar mass of compound is 58.0714g

18g of carbon, 3g of hydrogen, 8g of oxygen

no of moles of carbon = 18/12 = 1.5 moles

no of moles of hydrogen = 3/1 = 3

no of moles of oxygen = 8/16 = 1/2 = 0.5moles

C:H:O          = 1.5 : 3 : 0.5

                   = 3 : 6 : 1

Empirical formula = C₃H₆O

percentage composition of carbon (C%) = 3*12*100/58.0714 = 62%

percentage composition of of hydrogen(H%) = 6*1*100/58.0714 = 10%

percentage composition of of oxygen (O%) = 1*16**100/58.0714 =28%

molecular formula of compound is C₃H₆O