Q36. A gas mixture contains acetylene and carbon dioxide. 20 litre of this mixture requires 20 litre of oxygen under the same condition for complete combustion. The percentage of acetylene in the mixture is
(a) 50% (b) 40% (c) 60% (d) 75 %
Q37. 8.4 gram of a mixture of CaCO3 and MgCO3 on heating gives 4.0 gram of magnesium oxide. The volume of CO2 produced at STP in this process is
(a) 1.124 litre (b) 4.48 litre
(c) 2.24 litre (d) 3.36 litre
Ans-36) The reaction for the combustion of acetylene is C2H2+2.5O2→2CO2+H2O. The combustion of 1 mole (22.4 L) of acetylene will require 2.5 moles (2.5×22.4=56L)of oxygen. 20L of oxygen will combine with 22.456×20=8L of acetylene. Thus, the mixture contains 8L or 820×100=40% acetylene.