Ph Poh H Oh Calculator Formula

pH and pOH Formulas:

\[ pH = -\log_{10}[H^+] \] \[ pOH = -\log_{10}[OH^-] \] \[ [H^+] = 10^{-pH} \] \[ [OH^-] = 10^{-pOH} \] \[ pH + pOH = 14 \] \[ [H^+] \times [OH^-] = 10^{-14} \]

H+ Concentration:

mol/L

OH- Concentration:

mol/L

pH:

unitless

pOH:

unitless

Calculated H+ Concentration:

Calculated OH- Concentration:

Calculated pH:

Calculated pOH:

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1. What is pH and pOH?

pH and pOH are measures of the acidity and basicity of a solution, respectively. pH is defined as the negative logarithm of the hydrogen ion concentration, while pOH is the negative logarithm of the hydroxide ion concentration. The sum of pH and pOH always equals 14 at 25°C.

2. How Does the Calculator Work?

The calculator uses the following formulas:

\[ pH = -\log_{10}[H^+] \] \[ pOH = -\log_{10}[OH^-] \] \[ [H^+] = 10^{-pH} \] \[ [OH^-] = 10^{-pOH} \] \[ pH + pOH = 14 \] \[ [H^+] \times [OH^-] = 10^{-14} \]

Where:

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

Explanation: These equations show the logarithmic relationship between ion concentrations and pH/pOH values, and the inverse relationship between acidity and basicity.

3. Importance of pH Calculation

Details: pH measurement is crucial in many fields including chemistry, biology, medicine, environmental science, and industry. It affects chemical reactions, biological processes, and material properties.

4. Using the Calculator

Tips: Enter any one known value (H+ concentration, OH- concentration, pH, or pOH) and the calculator will compute the other three values. All concentrations should be in mol/L.

5. Frequently Asked Questions (FAQ)

Q1: What is the relationship between pH and pOH?
A: pH + pOH = 14 at 25°C. This is derived from the water dissociation constant Kw = [H+][OH-] = 10^-14.

Q2: What are normal pH values for common substances?
A: Pure water has pH 7, lemon juice ~2, vinegar ~3, coffee ~5, blood ~7.4, seawater ~8, bleach ~13.

Q3: How does temperature affect pH?
A: The pH of pure water decreases with increasing temperature, but the neutrality point (where [H+] = [OH-]) remains at pH 7.

Q4: Why use logarithmic scale for pH?
A: The logarithmic scale compresses the wide range of hydrogen ion concentrations (10^0 to 10^-14 M) into a manageable 0-14 scale.

Q5: How accurate are pH calculations?
A: These calculations assume ideal conditions at 25°C. Real solutions may show deviations due to ionic strength, temperature variations, and other factors.