Question

128 mL of 1.50 x 10-2 M NaOH is used to titrate 225 mL of a monoprotic acid with unknown concentration to reach the equivalence point. What is the concentration of the original acid?
Answer 1.50 x 10-2 M
1.17 x 10-1 M
1.92 x 10-3 M
8.53 x 10-3 M

Answer 1

since it's a monoprotic acid, 1 \(H^+\) is consumed for every \(OH^-\)

so you can use: \(M_1V_1=M_2V_2\)