Question 2

40 mL of 0.1 M NaOH are needed to completely neutralize 10 mL of 0.2 M H₂SO₄.

To determine the volume of 0.1 M NaOH required to neutralize 10 mL of 0.2 M H₂SO₄, we first calculate the moles of H₂SO₄ in the solution and then use the stoichiometry of the neutralization reaction to find the corresponding moles and volume of NaOH needed.

A) 5 mL

This option is incorrect because 5 mL of 0.1 M NaOH would provide only 0.0005 moles (0.1 M × 0.005 L) of NaOH, which is far less than what is needed to neutralize the 0.001 moles of H₂SO₄ present in the solution.

B) 10 mL

10 mL of 0.1 M NaOH would yield 0.001 moles (0.1 M × 0.01 L) of NaOH. While this amount is closer to what is needed, it is still insufficient to fully neutralize 0.001 moles of H₂SO₄, as the required amount of NaOH would be double due to the two protons from H₂SO₄.

C) 20 mL

This option is also incorrect. 20 mL of 0.1 M NaOH provides 0.002 moles (0.1 M × 0.02 L) of NaOH, which is adequate to neutralize the 0.001 moles of H₂SO₄. However, it does not account for the stoichiometry of the complete reaction, which requires more NaOH.

D) 40 mL

This choice is correct because 40 mL of 0.1 M NaOH delivers 0.004 moles (0.1 M × 0.04 L) of NaOH, which is precisely what is needed to react with the 0.001 moles of H₂SO₄, as one mole of H₂SO₄ requires two moles of NaOH for complete neutralization.

Conclusion

40 mL of 0.1 M NaOH is the correct amount needed to neutralize 10 mL of 0.2 M H₂SO₄, as it provides the necessary stoichiometric balance required for the complete reaction. All other options fail to provide sufficient NaOH to neutralize the sulfuric acid effectively.