One liter of 1 M NaOH will completely neutralize one liter of

• A. 1 M H2SO4
• B. 0.5 M H2SO4
• C. 2 M H2SO4
• D. 1.5 M H2SO4

Answer: (B)

Neutralization of a diprotic acid like sulfuric acid requires two moles of base per mole of acid, since H2SO4 has two acidic hydrogens that can be neutralized by hydroxide. With 1 liter of 1 M NaOH, you have 1 mole of NaOH. Each mole of H2SO4 needs 2 moles of NaOH to be fully neutralized, so 1 mole of NaOH can neutralize 0.5 mole of H2SO4. In 1 liter, 0.5 mole corresponds to a 0.5 M H2SO4 solution. Therefore, 1 L of 1 M NaOH will completely neutralize 1 L of 0.5 M H2SO4.