Which solution has the greatest percent ionization? (a) 0.010 m formic acid (ka = 1.8  10–4 ) (b) 0.10 m formic acid (ka = 1.8  10–4 ) (c) 0.010 m acetic acid (ka = 1.8  10–5 ) (d) 0.10 m acetic acid (ka = 1.8  10–5 )?

A high ka value means that the acid has a higher dissociation rate, leading to a higher percent of ionization. The answer is therefore b, as 0.1M formic acid has a higher ka than 0.1M acetic acid and 0.1M formic acid has a higher concentration than 0.01M formic acid.