Find the molarity of a sulfuric acid solution

Question

10.0 mL of the acid are placed into a flask along the appropriate indicator. It requires 24.7 mL of 0.189 M NaOH to reach the equivalence point. What is the molarity of the acid? Remember that H2SO4 is diprotic.

Answer 1

The balanced chemical equation for the reaction between sulfuric acid (H2SO4) and sodium hydroxide (NaOH) is:

H2SO4 + 2 NaOH → Na2SO4 + 2 H2O

From this equation, we can see that one mole of sulfuric acid reacts with two moles of sodium hydroxide.

First, we need to calculate the number of moles of NaOH used in the titration:

moles of NaOH = M x V (in liters) = 0.189 M x 0.0247 L = 0.00467 mol

Since one mole of sulfuric acid reacts with two moles of NaOH, the number of moles of sulfuric acid in the solution is:

moles of H2SO4 = 0.00467 mol / 2 = 0.00234 mol

Now we can use the formula:

molarity = moles / volume (in liters)

to calculate the molarity of the sulfuric acid:

molarity = 0.00234 mol / 0.0100 L = 0.234 M

Therefore, the molarity of the sulfuric acid solution is 0.234 M.