Ph Poh H Oh Calculator

pH, pOH, H, OH Relationships:

\[ pH = -\log[H^+], \quad pOH = -\log[OH^-] \] \[ pH + pOH = 14, \quad [H^+] = 10^{-pH}, \quad [OH^-] = 10^{-pOH} \]

Calculated Results:

pH:

pOH:

[H⁺]:

[OH⁻]:

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is pH, pOH, H, OH Calculator?

This calculator determines the relationships between pH, pOH, hydrogen ion concentration [H⁺], and hydroxide ion concentration [OH⁻] in aqueous solutions. These parameters are fundamental to understanding acid-base chemistry.

2. How Does the Calculator Work?

The calculator uses the following mathematical relationships:

\[ pH = -\log[H^+], \quad pOH = -\log[OH^-] \] \[ pH + pOH = 14, \quad [H^+] = 10^{-pH}, \quad [OH^-] = 10^{-pOH} \]

Where:

\( pH \) — Measure of acidity (0-14 scale)
\( pOH \) — Measure of basicity (0-14 scale)
\( [H^+] \) — Hydrogen ion concentration (mol/L)
\( [OH^-] \) — Hydroxide ion concentration (mol/L)

Explanation: These equations are derived from the ion product of water (K_w = 1.0 × 10⁻¹⁴ at 25°C) and the definition of pH and pOH scales.

3. Importance of pH and pOH Calculation

Details: Accurate calculation of these parameters is essential for chemical analysis, water treatment, biological systems, industrial processes, and environmental monitoring.

4. Using the Calculator

Tips: Enter any one known value (pH, pOH, [H⁺], or [OH⁻]) and the calculator will compute the other three values. Values must be within valid ranges (pH/pOH: 0-14, concentrations: 1e-14 to 1 mol/L).

5. Frequently Asked Questions (FAQ)

Q1: What is the relationship between pH and pOH?
A: pH + pOH = 14 at 25°C. This relationship comes from the ion product of water where [H⁺][OH⁻] = 1.0 × 10⁻¹⁴.

Q2: What are typical pH values for common substances?
A: Battery acid: ~0, Lemon juice: ~2, Pure water: 7, Sea water: ~8, Bleach: ~13.

Q3: How does temperature affect these calculations?
A: The ion product of water changes with temperature, so the relationship pH + pOH = pK_w varies slightly from 14 at different temperatures.

Q4: What is the significance of logarithmic scales?
A: pH and pOH use logarithmic scales to conveniently represent the wide range of hydrogen and hydroxide ion concentrations (from 1 to 10⁻¹⁴ mol/L).

Q5: Can this calculator be used for concentrated solutions?
A: For highly concentrated solutions (>1M), activity coefficients should be considered as the simple relationships may not hold accurately.