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The titration of a 20.0 ml sample of an H₂SO₄ solution of unknown concentration requires 22.60 ml of a 0.155 M KOH solution to reach the equivalence point. What is the concentration of the H₂SO₄ solution?

User Oxfn
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Final answer:

The concentration of the H₂SO₄ solution is calculated using the volume and molarity of KOH, and the stoichiometry of the titration reaction. Moles of KOH are used to find moles of H₂SO₄, which are then used to calculate the molarity of H₂SO₄ as 0.087575 M.

Step-by-step explanation:

To calculate the concentration of the H₂SO₄ solution, we must first understand the balanced chemical equation for the reaction of sulfuric acid with potassium hydroxide:

H₂SO₄ (aq) + 2KOH (aq) → K₂SO₄ (aq) + 2H₂O (l)

This equation tells us that each mole of H₂SO₄ reacts with 2 moles of KOH. Once we have the moles of KOH used in the titration, we can calculate the moles of H₂SO₄ because they react in a 1:2 ratio. The moles of KOH is the product of the volume in liters of the KOH solution and its molarity.

Moles of KOH = Volume of KOH x Molarity of KOH

Moles of KOH = 0.02260 L x 0.155 M = 0.003503 moles

Since 2 moles of KOH are required for each mole of H₂SO₄, the moles of H₂SO₄ will be half of the moles of KOH.

Moles of H₂SO₄ = Moles of KOH / 2 = 0.003503 moles / 2 = 0.0017515 moles

Finally, we find the molarity of the H₂SO₄ solution by dividing the moles of H₂SO₄ by the volume of the solution in liters.

Molarity of H₂SO₄ = Moles of H₂SO₄ / Volume of H₂SO₄ solution in liters

Molarity of H₂SO₄ = 0.0017515 moles / 0.02000 L = 0.087575 M

The concentration of the H₂SO₄ solution is 0.087575 M.

User Shahar Gvirtz
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