Question

How many liters of 0.200 m sodium hydroxide do you need to titrate 0.400 l of a 0.100 m diprotic acid to the equivalence point? 0.400 l naoh

Answer 1

• 0.400 liter

Step-by-step 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:

• M =n / V (in liter) ⇒ n = M×V = 0.100 M × 0.400 liter = 0.0400 mol

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:

• M = n / V (in liters) ⇒ V = n / M = 0.0800 mol / 0.200 M = 0.400 liter

That is the answer: 0.400 liter of 0.200 M sodium hydroxide.