What volume of a 0. 113M hydroiodic acid solution is required to neutralize 18.1 mL of a 0. 105M sodium hydroxide solution? mL hydroiodic acid
The correct answer and explanation is:
To find the volume of hydroiodic acid (HI) solution required to neutralize a given volume of sodium hydroxide (NaOH) solution, use the concept of neutralization based on molarity and volume.
Step 1: Write the balanced chemical equation
HI (aq) + NaOH (aq) → NaI (aq) + H₂O (l)
This reaction shows that 1 mole of hydroiodic acid reacts with 1 mole of sodium hydroxide.
Step 2: Use the neutralization formula
M₁ × V₁ = M₂ × V₂
Where:
- M₁ = molarity of HI (acid) = 0.113 M
- V₁ = volume of HI (acid) solution (unknown, in liters or milliliters)
- M₂ = molarity of NaOH (base) = 0.105 M
- V₂ = volume of NaOH solution = 18.1 mL
Since the reaction is 1:1, the moles of acid equal moles of base at neutralization.
Step 3: Solve for V₁
V₁ = (M₂ × V₂) / M₁
V₁ = (0.105 M × 18.1 mL) / 0.113 M
V₁ = (1.9005) / 0.113
V₁ ≈ 16.82 mL
Answer: Approximately 16.82 mL of 0.113 M hydroiodic acid is required to neutralize 18.1 mL of 0.105 M sodium hydroxide.
Explanation
Neutralization occurs when an acid and a base react in equivalent amounts, meaning the number of moles of hydrogen ions (H⁺) from the acid equals the number of moles of hydroxide ions (OH⁻) from the base. Molarity (M) defines the concentration of a solution in moles of solute per liter of solution.
To calculate how much acid is needed, first understand that the moles of acid required equals the moles of base present. The formula M × V = moles allows calculation of moles from concentration and volume. Since the molar ratio of acid to base is 1:1, multiply the molarity of the base by its volume to find moles of base. Then divide by the molarity of the acid to find the volume of acid required.
This approach is standard for titration or neutralization calculations, assuming complete reaction and equal molar ratios. The result is in milliliters since the volumes are given in milliliters. This calculation ensures the precise volume of acid needed for complete neutralization without excess.