Consider the K_a Values for the Following Acids

Multiple Choice

Consider the K_a values for the following acids:
Cyanic acid,HOCN,3.5 × 10^-4
Formic acid,HCHO₂,1.7 × 10^-4
Lactic acid,HC₃H₅O₃,1.3 × 10^-4
Propionic acid,HC₃H₅O₂,1.3 × 10^-5
Benzoic acid,HC₇H₅O₂,6.3 × 10^-5
Given initially equimolar soutions of each weak acid,which solution will have the highest hydronium ion concentration once equilibrium is established?

A) cyanic acid
B) benzoic acid
C) lactic acid
D) formic acid
E) propionic acid