[H+]*[Ac-]/[HAc] =10^-4.77[[Ac-]/[HAc] =10^-4.77/10^-5 =10^0.23[[Ac-]= 10^0.23 *0.05[HAc] =0.05M6V(NaOH)=10^0.23*0.5*150V(NaOH)=12.5*10^0.23ml{[10^0.23 *0.05+0.05M}*150=0.5V(HAc)V(HAc)={[10^0.23 *0.05+0.05M}*300ml