What volume of oxygen at S.T.P is required to effect complete combustion of 200 cubic centemeter of acetylene and what would be the volume of carbon dioxide formed?

2C₂H₂ + 5O₂ ?   4CO₂ +  2H₂0

 

2vol        5vol       4vol       2vol

 

2vol of C₂H₂  uses 5vol of O₂ for combustion

Therefore, 200cm³ of C₂H_{2 =} 5 x 200/ 2

                                                           = 500cm³

 

By Gay Lussac's law 2vol of C₂H_{2 =} 4vol of CO₂

 

Thus, 200cm³ of C₂H₂ = 4 x 200/2

                                 = 400cm³ of CO₂ at STP