欲配制 pH=5.6 缓冲溶液,应选用( )
A.HCOOH–HCOONa [ pKθa (HCOOH) = 3.75 ] B.HAc–NaAc [ pKθa (HAc) = 4.74 ] C.NaH2PO4–Na2HPO4 [ pKθa (H3PO4) = 7.21 ] D.NH3∙H2O–NH4Cl [ pKθb (NH3) = 4.75 ]正确答案B
欲配制 pH=5.6 缓冲溶液,应选用( )
A.HCOOH–HCOONa [ pKθa (HCOOH) = 3.75 ] B.HAc–NaAc [ pKθa (HAc) = 4.74 ] C.NaH2PO4–Na2HPO4 [ pKθa (H3PO4) = 7.21 ] D.NH3∙H2O–NH4Cl [ pKθb (NH3) = 4.75 ]正确答案B