Question

根据解离常数,选取合适的酸及其共轭酸碱或合适的碱及其共轭酸碱来配制ph=4.5和ph=9.5的缓冲溶液

Answer 1

pH=4.5 ===》HAc/Ac-

pH=9.5 ===>HCO3-/CO32-

pH = pKa + log([Ac-]/[HAc])

5 = 4.74 + log([Ac-]/0.2)

所以,[Ac-]=0.2x10^0.26=0.364 mol/L

V(HAc)=0.2x1000/1=200 mL

V(Ac-]=0.364x1000/1=364 mL