Math Problem Statement

in a titration, a sample of H2SO4 solution with a volume of 15.00 mL required 36.42 mL of 0.147 M NaOH for complete reaction. What is the molarity of the H2SO4 solution?

Solution

To solve this problem, let's start by writing the balanced chemical equation for the reaction between sulfuric acid (H₂SO₄) and sodium hydroxide (NaOH):

H2SO4+2NaOHNa2SO4+2H2O\text{H}_2\text{SO}_4 + 2\text{NaOH} \rightarrow \text{Na}_2\text{SO}_4 + 2\text{H}_2\text{O}

This equation tells us that one mole of sulfuric acid reacts with two moles of sodium hydroxide.

Step 1: Calculate the moles of NaOH used in the titration

The molarity (M) formula is: Molarity=moles of solutevolume of solution in liters\text{Molarity} = \frac{\text{moles of solute}}{\text{volume of solution in liters}}

Rearranging it to find the number of moles: moles of NaOH=Molarity×Volume (L)\text{moles of NaOH} = \text{Molarity} \times \text{Volume (L)}

Given:

  • Molarity of NaOH = 0.147 M
  • Volume of NaOH = 36.42 mL = 0.03642 L

moles of NaOH=0.147M×0.03642L=0.00535374moles\text{moles of NaOH} = 0.147 \, \text{M} \times 0.03642 \, \text{L} = 0.00535374 \, \text{moles}

Step 2: Determine the moles of H₂SO₄ reacted

From the balanced equation, 1 mole of H₂SO₄ reacts with 2 moles of NaOH, so we can use the stoichiometric ratio to find the moles of H₂SO₄:

moles of H2SO4=moles of NaOH2=0.005353742=0.00267687moles\text{moles of H}_2\text{SO}_4 = \frac{\text{moles of NaOH}}{2} = \frac{0.00535374}{2} = 0.00267687 \, \text{moles}

Step 3: Calculate the molarity of the H₂SO₄ solution

Using the molarity formula again: Molarity of H2SO4=moles of H2SO4volume of solution in liters\text{Molarity of H}_2\text{SO}_4 = \frac{\text{moles of H}_2\text{SO}_4}{\text{volume of solution in liters}}

Given:

  • Volume of H₂SO₄ = 15.00 mL = 0.01500 L

Molarity of H2SO4=0.00267687moles0.01500L=0.178M\text{Molarity of H}_2\text{SO}_4 = \frac{0.00267687 \, \text{moles}}{0.01500 \, \text{L}} = 0.178 \, \text{M}

Answer

The molarity of the H₂SO₄ solution is: 0.178M\boxed{0.178 \, \text{M}}

Would you like more details or have any questions on this calculation?

Here are five related questions to further explore this topic:

  1. What is the importance of using a balanced chemical equation in titration calculations?
  2. How do you determine the endpoint of a titration experimentally?
  3. What would happen if the NaOH concentration was incorrectly measured in a titration?
  4. How does a diprotic acid like H₂SO₄ affect the stoichiometry of a reaction?
  5. What is the role of an indicator in acid-base titrations?

Tip: Always make sure to convert volumes to liters when using the molarity formula to ensure consistency in units.

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Math Problem Analysis

Mathematical Concepts

Stoichiometry
Molarity Calculations
Titration

Formulas

Molarity = moles of solute / volume of solution in liters
moles of NaOH = Molarity × Volume (L)
moles of H2SO4 = moles of NaOH / 2

Theorems

Stoichiometry principles
Molarity theorem

Suitable Grade Level

Grades 11-12