Calculate the pH of each solution given the following:
f. [OH^-] = 8.2 × 10^-4 M

Verified step by step guidance

1. Step 1: Recall the relationship between pH, pOH, and the concentration of hydroxide ions ([OH⁻]). The formula to calculate pOH is: $\mathrm{pOH}=-\log \left({\mathrm{[OH]}}_{-}\right)$.
2. Step 2: Substitute the given [OH⁻] value (8.2 × 10⁻⁴ M) into the formula for pOH. This will give you the pOH of the solution.
3. Step 3: Use the relationship between pH and pOH, which is: $\mathrm{pH}=14-\mathrm{pOH}$. Subtract the calculated pOH from 14 to find the pH.
4. Step 4: Ensure that your final pH value is reasonable. For a solution with a relatively high [OH⁻], the pH should be greater than 7, indicating a basic solution.
5. Step 5: Double-check your calculations for accuracy, especially when using logarithms and subtraction, to ensure the correct pH value is obtained.

Key Concepts

pH Scale

The pH scale measures the acidity or basicity of a solution, ranging from 0 to 14. A pH of 7 is considered neutral, while values below 7 indicate acidity and values above 7 indicate alkalinity. The scale is logarithmic, meaning each whole number change represents a tenfold change in hydrogen ion concentration.

Hydroxide Ion Concentration

Hydroxide ions (OH⁻) are negatively charged ions that play a crucial role in determining the basicity of a solution. The concentration of hydroxide ions can be used to calculate the pOH of a solution, which is related to pH through the equation pH + pOH = 14. Understanding the concentration of OH⁻ is essential for calculating the corresponding pH.

Relationship Between pH and pOH

The relationship between pH and pOH is defined by the equation pH + pOH = 14 at 25°C. This means that if you know the pOH of a solution, you can easily find its pH by subtracting the pOH from 14. This relationship is fundamental in acid-base chemistry and is crucial for solving problems involving pH calculations.