A lactic acid/lactate buffer is prepared by dissolving 0.30 mol L lactic acid ( ) and…
CHEMISTRY · Single correct · A Level · Chemistry · Acids and bases · Acids and bases
Problem
A lactic acid/lactate buffer is prepared by dissolving 0.30 mol L−1 lactic acid (HLac) and 0.20 mol L−1 sodium lactate (NaLac) in 200 mL of solution. First, 5.0 mL of 2.0 M HCl are added; after mixing, 10.0 mL of 1.0 M NaOH are added. What is the pH after the second addition? (For lactic acid, pKa=3.86.)
(a) 3.56
(b) 4.00
(c) 3.68
(d) 3.86