Calculate Ph for 1.0 10 3 M Sr Oh 2

This calculator determines the pH of a solution given its hydroxide ion concentration ([OH⁻]). The pH scale measures how acidic or basic a solution is, with values ranging from 0 (most acidic) to 14 (most basic).

How to Calculate pH

The pH of a solution can be calculated using the hydroxide ion concentration. Here's the step-by-step process:

Measure the concentration of hydroxide ions ([OH⁻]) in moles per liter (M).
Use the pH formula: pH = 14 - pOH.
Calculate pOH using the hydroxide ion concentration: pOH = -log[OH⁻].
Subtract pOH from 14 to get the pH.

For example, if [OH⁻] = 1.0 × 10⁻³ M, the pH calculation would be:

Example Calculation

Given [OH⁻] = 1.0 × 10⁻³ M:

pOH = -log(1.0 × 10⁻³) = 3

pH = 14 - pOH = 14 - 3 = 11

The pH Formula

The pH of a solution is calculated using the following formula:

pH Calculation Formula

pH = 14 - pOH

where pOH = -log[OH⁻]

This formula is derived from the relationship between hydrogen ions ([H⁺]) and hydroxide ions ([OH⁻]) in water, which is governed by the ionization constant of water (Kw = 1.0 × 10⁻¹⁴ at 25°C).

Worked Example

Let's calculate the pH for a solution with [OH⁻] = 1.0 × 10⁻³ M:

First, calculate pOH: pOH = -log(1.0 × 10⁻³) = 3
Then, calculate pH: pH = 14 - pOH = 14 - 3 = 11

The result shows this solution has a pH of 11, which is basic.

Note

This calculation assumes standard temperature conditions (25°C). Temperature affects the ionization constant of water and thus the pH calculation.

Interpreting Results

The pH scale ranges from 0 to 14:

pH 0-6: Acidic solutions
pH 7: Neutral (pure water)
pH 8-14: Basic solutions

A pH of 11 indicates a strongly basic solution. This means the solution contains a high concentration of hydroxide ions, which can react with acids to neutralize them.

pH Scale Interpretation
pH Range	Solution Type	Common Examples
0-6	Acidic	Lemon juice, vinegar, stomach acid
7	Neutral	Pure water, distilled water
8-14	Basic	Soap, baking soda, bleach

FAQ

What is the relationship between pH and [OH⁻]?

The pH of a solution is inversely related to the hydroxide ion concentration. As [OH⁻] increases, pH increases, and vice versa. This relationship is described by the formula pH = 14 - pOH, where pOH = -log[OH⁻].

How does temperature affect pH calculations?

Temperature affects the ionization constant of water (Kw). At temperatures other than 25°C, Kw changes, which can alter pH calculations. This calculator assumes standard conditions (25°C).

What is the pH of a neutral solution?

A neutral solution has a pH of 7, which occurs when [H⁺] = [OH⁻] = 1.0 × 10⁻⁷ M at 25°C. Pure water is an example of a neutral solution.