Question

What volume of oxygen at ntp is needed to cause complete combustion of 200ml of ethyne?

Answer 1

2C2H2 + 5O2 ?   4CO2 +  2H20

 

2vol        5vol       4vol       2vol

 

2vol of C2H2  uses 5vol of O2 for combustion

Therefore, 200cm3 of C2H2 = 5 x 200/ 2

                                                          = 500cm3

 

By Gay Lussac's law 2vol of C2H2 = 4vol of CO2

 

Thus, 200cm3 of C2H2 = 4 x 200/2

                                = 400cm3 of CO2 at STP

Answer 2

your answer is 200ml cube of oxygen