53.9 mL of 0.991 M nitric acid is added to 45.3 mL of sodium hydroxide, and the resulting solution is found to be acidic.

20.5 mL of 1.51 M potassium hydroxide is required to reach neutrality.

What is the molarity of the original sodium hydroxide solution?

1 answer

Total mols HNO3 (too much) = M x L = ?
- mols KOH added to correct = M x L =
= mols HNO3 used to titrate the NaOH.
Then M NaOH = mols NaOH/L NaOH.
The answer is appox 0.5 M