Applications of Aqueous EquilibriaApplications of Aqueous Equilibria

What quantity (moles) of NaOH must be added to 1.0 L of 2.5 M HC2H3O2 to produce a solution buffered at pH = pKa?Ka = 1.8E-5

What quantity (moles) of NaOH must be added to 1.0 L of 1.9 M HC2H3O2 to produce a solution buffered at pH = 5.00?Ka = 1.8E-5