1. What is the Calculate pH from Ka?

Definition: This calculator determines the pH, pOH, [H⁺], and [OH⁻] of a solution based on the Ka (acid dissociation constant) and concentration of a weak acid, with customizable units for both input and output.

Purpose: It helps chemists, students, and researchers calculate pH and ion concentrations for weak acid solutions, useful in chemistry, biology, and environmental science.

2. How Does the Calculator Work?

The calculator uses these principles:

Where:

• \( K_a \) — Acid dissociation constant (user-provided).
• \( [\text{H}^+] \) — Hydrogen ion concentration (calculated using the quadratic formula: \( [\text{H}^+]^2 + K_a[\text{H}^+] - K_a \times \text{Concentration} = 0 \)).
• Units for concentration and outputs can be M, mM, µM, nM, pM, or fM.

Explanation: Enter a valid Ka value, input the concentration with its unit, choose the output units for [H⁺] and [OH⁻], and click "Calculate." Results show pH, pOH, [H⁺], and [OH⁻] in the chosen units, with values < 0.00001 displayed in scientific notation.

3. Importance of pH, pOH, [H⁺], and [OH⁻] Calculation

Details: These measurements are crucial for understanding acidity and basicity, biological processes, industrial applications, and environmental conditions. Accurate values help in chemical reactions, buffer design, and health assessments.

4. Using the Calculator

Tips: Enter a positive Ka value (e.g., 1.8e-5 for acetic acid), input a positive concentration with its unit, select the [H⁺] and [OH⁻] output units, and click "Calculate." Ensure Ka is in decimal or scientific notation (e.g., 1.8e-5). Results are displayed with scientific notation for values < 0.00001.