You Have 75 $\times$ 10^-6
B) 1 $\times$ 10^-6
C) 0 $\times$ 10^-6
E) None of These

Multiple Choice

You have 75.0 mL of 0.11 M HA.After adding 30.0 mL of 0.10 M NaOH,the pH is 5.50.What is the K_a value of HA?

A) 3.2 $\times$ 10^-6
B) 1.8 $\times$ 10^-6
C) 0.57
D) 1.1 $\times$ 10^-6
E) none of these