at 100C the gaseous reaction A==2B+C is observed to be first order.on starting with pure A it is found that at the end of 10min,the total pressure of the system is 176mmHg,and after a long time the total pressure of the system is 270mmHg.a).determine the initial pressure of A :b).the pressure of A at the end of 10 minutes:c).half period of the reaction.