When Values of K_a Are Small (E

Multiple Choice

When values of K_a are small (e.g., 1  10^5) and concentrations of weak acids [HA] are relatively large (e.g., 0.10 M) , the hydronium ion concentration of the solution can be calculated using which expression?

A) [H^]  K_a
B) [H^]  K_a[HA]
C) [H^]  (K_a[HA]) ^1/2
D) [H^]  K_aK_b[HA]
E) [H^]  K_a[HA]/[A^]