Question

0.26 g of an organic compound gave 0.039 g of water and 0.245 g of carbon dioxide on combustion. Calculate the percentage of C & H.

Answer 1

Weight of organic compound = 0.26 g

Weight of water = 0.039 g

Weight of CO₂ = 0.245 g

Percentage of hydrogen:

18 g of water contains 2 g of hydrogen

0.039 g of water contains = \(\frac{2}{18}\) x \(\frac{0.039}{0.26}\) of H

% of hydrogen = \(\frac{0.039}{0.26}\) x \(\frac{2}{18}\) x 100 = 1.66%

Percentage of carbon:

44 g of CO₂ contains 12 g of C

0.245 g of CO₂ contains = \(\frac{12}{44}\) x \(\frac{0.245}{0.26}\) g of C

% of Carbon = \(\frac{12}{44}\) x \(\frac{0.245}{0.26}\) x 100 = 25.69%