Answer:
Explanation:
Since, the acid is diprotic, you have that 1 mol of it releases 2 mol of hydrogen ions, H⁺.
Determine the number of moles of acid, using the molarity definition:
And the number of moles of H⁺ ions equals 2 × 0.0400 mol = 0.0800 mol
At the equivalence point of the titration the number of moles of H⁺ from the acid equals the number of moles of OH⁻ from the base.
Since, sodium hydroxide ionizes in a ratio 1 : 1 (1 mol of NaOH / 1 mol OH⁻), the number of moles of NaOH is equal to 0.0800 mol
And now you use the molarity definition for the 0.200 M sodium hydroxide solution:
That is the answer: 0.400 liter of 0.200 M sodium hydroxide.