21 Combustion of a 09835g sample of a compound containing on

21) Combustion of a 0.9835-g sample of a compound containing only carbon, hydrogen, and oxygen produced 1.900 g of CO2 and 1.070 g of H20. What is the empirical formula of the compound? A) C4H1102 B) C2H502 D) C4H1002 E) C2H50

Solution

21) No of mol of CO2 = 1.9/44 = 0.0432 mol

No of mol of C = 0.0432 mol

nO of mol of H2O = 1.070/18 = 0.05945 mol

NO OF MOL OF H = 0.05945*2 = 0.119 mol

nO mol of O = (0.9835-(0.0432*12+0.119*1))/16

             = 0.0216 mol

simplest ratio,

C = 0.0432/0.0216 = 2

H = 0.119/0.0216 = 5.5

O = 0.0216/0.0216 = 1

empirical formula

WHOLE NUMBER RATIO

(c2H5.5O) *2 = C4H11O2

ANSWER: A