Answer to Question #328246 in General Chemistry for Umi

Question

Compound X contains only carbon, hydrogen and oxygen. A 0.2000 g sample of compound X was burnt completely in a combustion vessel to yield 0.3906 g of C02 and 0.200 g of H20. Determine the empirical formula of compound X.

Answer 1

$C_xH_yO_z +O_2 \rightarrow CO_2 + H_2O$

M(CO₂)=12+16x2=44 g/mol

M(H₂O)=2x1+16=18 g/mol

n(CO₂)=0.3906/44=0.00888 mol

n(C)=n(CO₂)=0.00888 mol

n(O_CO2)=2n(CO₂)=0.0178 mol

n(H₂O)=0.2/18=0.0111 mol

n(H)=2n(H₂O)=0.0222 mol

n(O_H2O)=n(H₂O)=0.0111:mol

n(O)=n(O)_CO2+n(O)_H2O=0.0178+0.0111=0.0289 mol

Let delete all on n(C)

C-1

H-2.5

O-3.25

Then substance is $C_xH_{2.5x}O_{3.25x}$

Formula is $C_4H_{10}O_{13}$