The pH of a solution resulting when 50 mL of 0.2 M HCI is mixed with 50 mL of 0.20 M AcOH (Ka = 1.8 x 10-5) is

In a mixture of weak acid (resultant concentration C1 mot L-1 and ionisation constant  K1) and a strong acid (resultant concentration C2 mol L-1), total [H3O+l isH3O+=C2+C22+4K1C12 Due to dilution by one another,C1(ACOH)=0.22=0.1M C2(HCl)=0.22=0.1M ∴ H3O+=(0.1)+(0.1)2+4×1.8×10−5×0.12=0.1M ∴ pH=−log⁡H3O+=1 Alternately AcOH is a weak acid. Its H3O+<<<0.2M. It simply caused dilution of HCI. Resultant concentration due to dilution,[HCl]=0.2×50100=0.1M∴ pH=1