How many milliliters of 1.00 M KOH must be added to neutralize the following solutions? (b) A mixture of 0.300 M HCl (45.0 mL) and 0.250 M NaOH (10.0 mL)

Verified step by step guidance

1. Calculate the moles of HCl in the solution using the formula: \( \text{moles of HCl} = \text{concentration} \times \text{volume} \).
2. Calculate the moles of NaOH in the solution using the formula: \( \text{moles of NaOH} = \text{concentration} \times \text{volume} \).
3. Determine the net moles of HCl remaining after the reaction with NaOH by subtracting the moles of NaOH from the moles of HCl.
4. Use the net moles of HCl to find the volume of 1.00 M KOH needed for neutralization using the formula: \( \text{volume of KOH} = \frac{\text{moles of HCl}}{\text{concentration of KOH}} \).
5. Convert the volume of KOH from liters to milliliters by multiplying by 1000.

Key Concepts

Neutralization Reaction

A neutralization reaction occurs when an acid reacts with a base to produce water and a salt. In this case, hydrochloric acid (HCl) and potassium hydroxide (KOH) will react to form water and potassium chloride (KCl). Understanding the stoichiometry of this reaction is essential for calculating the amounts of reactants needed for complete neutralization.

Molarity and Volume Calculations

Molarity (M) is a measure of concentration defined as moles of solute per liter of solution. To find the number of moles of HCl and NaOH in the mixture, we can use the formula: moles = molarity × volume (in liters). This calculation is crucial for determining how much KOH is required to neutralize the total moles of acid present.

Stoichiometry

Stoichiometry involves the calculation of reactants and products in chemical reactions based on balanced equations. For the neutralization of HCl by KOH, the balanced equation shows a 1:1 molar ratio. This means that the moles of KOH needed will equal the moles of HCl after accounting for any NaOH present, allowing for accurate determination of the volume of KOH required.