What is the simplest formula of the compound which has the following percentage composition - Carbon 80%. Hydrogen 20% ? If the molecular mass is 30, calculate its molecular formula.

Explanation

Calculation of empirical formula.
`|{:("Element","% age","Atomic","Constent","No of","Sample","Simplest whole"),(,," mass","in sample","moles"," ratio"," no. ratio"),(" C"," 80"," 12"," 80 g",(80)/(12)=6.66,(6.66)/(6.66)=1," 1"),(" H"," 20"," 1"," 20 g",(20)/(1)=20,(20)/(6.66)=3," 3"):}|`
`therefore` Empirical formula is `CH_(3)`
Calculation of molecular formula
Empirical formula mass `=12xx1+1xx3=15`
`n=("Molecular mass")/("Empirical formula mass")=(30)/(15)=2`
Molecular formula = Empirical formula `xx2`
`= CH_(3)xx2=C_(2)H_(6)` .