Question

1.6 g of an organic compound on combustion gave 4.4 g of CO2. find the % of carbon in organic compound?

Answer 1

Combustion equations are used to find empirical formulas. This can also be referred to as elemental analysis.  Here is how we can get the percentage:

First, calculate the molar mass of CO2


The molar mass of CO2= (12+16x2) =44

Atomic mass of carbon is 12

Calculate weight of carbon in the 4.4g CO2;

= 12/44 x 4.4  = 1.2 grams

that  means the mass of carbon in the compound was 1.2 grams

Calculate the % mass of C in the compound of total weight 1.6g

= 1.2/1.6 x 100
= 75 %
There % of carbon in the compound = 75%