A 200.0 ml quantity of 0.9 M HCl was titrated with an NaOH solution to reach the equivalence point. The goal was to determine the concentration of the NaOH solution. if 23.9 ml if the NaOH solution was required, what was the [NaOH]???

Since the acid and base react in a one to one ratio, you can use the equation M1V1 = M2V2 to solve for M2, or the molarity of NaOH.

M1 = 0.9 M HCl

V1 = 200.0 mL HCl

M2 = ?

V2 = 23.9 mL NaOH

(0.9 M)(200.0 mL) = M2(23.9 mL) —> M2 = 7.53 M NaOH

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