pH/pOH Calculations of Strong Acids/Bases

Front

What is pH?

Back

pH is a measure of the hydrogen ion concentration in a solution, defined as pH = -log[H⁺]. It indicates how acidic or basic a solution is.

Front

What is pOH?

Back

pOH is a measure of the hydroxide ion concentration in a solution, defined as pOH = -log[OH⁻]. It indicates how basic a solution is.

Front

What is the relationship between pH and pOH?

Back

pH + pOH = 14 at 25°C. This relationship shows that as the acidity of a solution increases (lower pH), the basicity decreases (higher pOH), and vice versa.

Front

How do you calculate the [H⁺] from pH?

Back

To find the hydrogen ion concentration from pH, use the formula [H⁺] = 10^(-pH).

Front

How do you calculate the pH from [H⁺]?

Back

To find the pH from the hydrogen ion concentration, use the formula pH = -log[H⁺].

Front

What is the [H⁺] concentration of a neutral solution at 25°C?

Back

In a neutral solution at 25°C, [H⁺] = 1.0 x 10⁻⁷ M.

Front

What is the [OH⁻] concentration of a neutral solution at 25°C?

Back

In a neutral solution at 25°C, [OH⁻] = 1.0 x 10⁻⁷ M.

Front

How do you find [OH⁻] from [H⁺]?

Back

Use the formula [OH⁻] = 1.0 x 10⁻¹⁴ / [H⁺]. This is derived from the water dissociation constant (Kw).

Front

What is the pH of a solution with [H⁺] = 1.0 x 10⁻³ M?

Back

pH = -log(1.0 x 10⁻³) = 3.

Front

What is the pOH of a solution with [OH⁻] = 1.0 x 10⁻¹¹ M?

Back

pOH = -log(1.0 x 10⁻¹¹) = 11.