A compound contains 40% carbon, 6.6% hydroaen and 53.33% oxy1en._Its vapour density is 30. Calculate its empirical and molecular formulae.

A compound contains 40% carbon, 6.6% hydroaen and 53.33% oxy1en._Its v

1.	A compound contains 40% carbon, 6.6% hydroaen and 53.33% oxy1en._Its vapour density is 30. Calculate its empirical and molecular formulae.
Answer» Solution :Calculation of empirical formula : The SUM of percentages of C and H in the given compound is not 100. Therefore, it must contain oxygen also. Percentage of O = `100 - (40 + 6.67) = 53.33`. The empirical formula of this compound can be obtained as follows : `therefore` The empirical formula of the given compound is `CH_(2)O` Calculation of molecular formula : Empirical formula mass = `12.01 + (2 xx 1.008) + 16.0 = 30.0` amu Molecular mass (given) = 30.0 amu Molecular mass `therefore n=("Molecular mass")/("Empirical formula mass")=30.0/30.0 =1` `therefore` Molecular formula `=1 xx` Empirical formula =`CH_(2)O` HENCE, the molecular formula of the given compound is the same as its empirical formula and is `CH_(2)O`