What volume of 0.855 M KOH solution is required to make 3.55 L of a solution with a pH of 12.4?

Verified step by step guidance

Determine the concentration of hydroxide ions \([OH^-]\) in the solution with a pH of 12.4 using the formula \(pOH = 14 - pH\).

Calculate \([OH^-]\) using the formula \([OH^-] = 10^{-pOH}\).

Use the dilution equation \(M_1V_1 = M_2V_2\) where \(M_1\) is the initial concentration of KOH, \(V_1\) is the volume of KOH solution needed, \(M_2\) is the concentration of \([OH^-]\) in the final solution, and \(V_2\) is the final volume of the solution.

Rearrange the dilution equation to solve for \(V_1\): \(V_1 = \frac{M_2V_2}{M_1}\).

Substitute the known values into the equation to find \(V_1\), the volume of 0.855 M KOH solution required.

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Molarity (M)

Molarity is a measure of concentration defined as the number of moles of solute per liter of solution. It is expressed in moles per liter (mol/L). Understanding molarity is crucial for calculating how much solute is needed to achieve a desired concentration in a solution.

pH and pOH

pH is a logarithmic scale used to specify the acidity or basicity of a solution, with lower values indicating higher acidity and higher values indicating higher basicity. The pH scale ranges from 0 to 14, where a pH of 7 is neutral. The relationship between pH and pOH is given by the equation pH + pOH = 14, which is essential for determining the concentration of hydroxide ions in basic solutions.

Neutralization and Stoichiometry

Neutralization is a chemical reaction between an acid and a base that produces water and a salt. Stoichiometry involves using balanced chemical equations to calculate the amounts of reactants and products in a reaction. In this context, understanding the stoichiometric relationships helps determine how much KOH is needed to achieve the desired pH by calculating the corresponding hydroxide ion concentration.

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