Question

5.00 ml of an H2SO4 solution with unknown molarity was diluted with 25.00 ml. This was tirated with 15.00ml of .1000 M NaOH to reach the equivalence point. What is the molarity of the original unknown H2SO4 solution? Also, what would the balanced chemical equation for this reaction be?

Answer 1

0.1500 M

H₂SO₄ + 2NaOH → Na₂SO₄ + 2H₂O

Step-by-step explanation:

The balanced chemical equation is:

• H₂SO₄ + 2NaOH → Na₂SO₄ + 2H₂O

First we calculate how many NaOH moles reacted, using the volume and concentration:

• 15.00 mL * 0.100 M = 1.5 mmol NaOH

Then we convert NaOH moles into H₂SO₄ moles:

• 1.5 mmol NaOH *
  `(1mmolH_2SO_4)/(2mmolNaOH)` = 0.75 mmol H₂SO₄

This amount of H₂SO₄ moles was originally contained within 5.00 mL of solution, thus the molarity is:

• 0.75 mmol H₂SO₄ / 5.00 mL = 0.1500 M