[" 9.A buffer solution contains "100mL" of "0.01M],[CH_(3)COOH" and "200mL" of "0.02M],[CH_(3)COONa.700mL" of water is added."pH],[" before and after dilution are ":(pK_(a)=4.74)],[[" (1) "5.04,5.04," (2) "5.04,0.504],[" (3) "5.04,1.54," (4) "5.34,5.34]]