Which Aqueous Solution Has the Highest PH

Multiple Choice

Which aqueous solution has the highest pH?

A) 0.1 M CH₃COOH, pK_a = 4.7
B) 0.1 M CuCl₂, pK_a = 7.5
C) 0.1 M H₃C₆H₅O₇, pK_a = 3.1
D) 0.1 M ZnCl₂, pK_a = 9.0
E) pure water