Some Basic Concepts of Chemistry Part 1

CxHy+(x+‌

y

4

)O2⟶xCO2+‌

y

2

H2O
Any hydrocarbon, on combustion gives CO2 and H2O. This is Liebig's method for estimation of ' C ' and ' H′ percentage.
Mass of water formed =210g
18g of H2O contains =2g of hydrogen
210g of H2O contains =(‌

2

18

×210=‌

70

3

)g of hydrogen.
Given, mass of organic compound =750g
Percentage of hydrogen
=‌

‌ Mass of hydrogen ‌

‌ Mass of organic compound ‌

×100
=‌

70

3×750

×100
=3.11%
Nearest integer =3