Q A solution of A is mixed with an equal volumes of a solution of B containing the same number of moles and and the reaction A+B=C occurs.

        At the end of 1h ,A is 75%  reacted.How much of A will be left unreacted at end of 2h if the reaction is

1.       First order in both A and B

(A)12.5%                (B)14.3%                       (C)6.25%                       (D)5%

{ans-B}

2.zero order in both A and B

(A)12.5%                (B)14.3%                       (C)6.25%                       (D)0%

{ans-D}

For the second question,since the reaction is of zero order,A_t=A₀-kt,where k is rate constant

After 1h,A_t=A₀/4 means k=3/4A₀.So,A_t=A₀(1-3t/4) and hence A=0 after 4/3h and so,after 2h

For the first question,I also got C as the ans.