Answer :
To determine the molarity of the NaOH solution neutralized by H2SO4, calculate the number of moles of H2SO4 and use stoichiometry to find the number of moles of NaOH. The molarity of NaOH is the moles of NaOH divided by its volume in liters, giving a molarity of 0.350 M. Therefore, the correct option is B.
The molarity of a NaOH solution can be calculated when it is neutralized by a known concentration of H2SO4 solution. In the reaction between sulfuric acid and sodium hydroxide, the balanced chemical equation is:
H2SO4 (aq) + 2NaOH (aq) → Na2SO4 (aq) + 2H2O (l)
As per the stoichiometry of the balanced equation, 1 mole of H2SO4 reacts with 2 moles of NaOH. Using the given volumes and molarity of H2SO4, we can find the moles of NaOH. The number of moles of H2SO4 is:
Number of moles of H2SO4 = volume (L) * molarity (M)
= 0.0391 L * 0.112 M
= 0.004376 moles of H2SO4
Therefore, since 1 mole of H2SO4 reacts with 2 moles of NaOH:
Number of moles of NaOH = 2 * number of moles of H2SO4
= 2 * 0.004376 moles
= 0.008752 moles of NaOH
Finally, the molarity (M) of NaOH is:
Molarity of NaOH = moles of NaOH / volume (L) of NaOH solution
= 0.008752 moles / 0.025 L
= 0.350 M
Therefore, the correct answer is B) 0.350 M.
