An organic compound contains 69percent carbon and 4.8percent hydrogen, the remainder being oxygen.

Question

An organic compound contains 69% carbon and 4.8% hydrogen, the remainder being oxygen. Calculate the masses of carbon dioxide and water produced when 0.20 g of this substance is subjected to complete combustion.

Answer 1

Percentage of carbon in organic compound = 69 % 

That is, 100 g of organic compound contains 69 g of carbon. 

0.2 g of organic compound will contain =(69X0.2)100=0.138G OF c

Molecular mass of carbon dioxide, CO₂ = 44 g 

That is, 12 g of carbon is contained in 44 g of CO₂. 

Therefore, 0.138 g of carbon will be contained in (44X0.138)/12 = 0.506 g of CO₂ 

Thus, 0.506 g of CO₂ will be produced on complete combustion of 0.2 g of organic compound. Percentage of hydrogen in organic compound is 4.8. i.e., 100 g of organic compound contains 4.8 g of hydrogen. 

Therefore, 0.2 g of organic compound will contain  (4.8x0.2/100)=0.0096g of H

It is known that molecular mass of water (H₂O) is 18 g. Thus, 2 g of hydrogen is contained in 18 g of water. 

0.0096 g of hydrogen will be contained in (18X0.00096/2)=0.0864g of water 

Thus, 0.0864 g of water will be produced on complete combustion of 0.2 g of the organic compound.