Question

a weak monobasic acid as 0.04% dissociation in a 0.025M solution. what is pH of solution​

Answer 1

Answer:

the pH of solution is 5

Explanation:

pH = -log [ H3O+ ]

= - log [ 10 -⁵ ]

= 5

Answer 2

Given:

A weak monobasic acid with percentage dissociation = 0.04%

The molarity of the solution = 0.025M

To Find:

The pH of the solution

Solution:

The pH of the solution is 5.

The pH of a solution gives the measure of the concentration of hydronium ions in the solution.

According to the formula, pH = - log [H⁺]

Here [H⁺] is the concentration of H⁺ ions.

A weak monobasic aid (HA) dissociates into two ions H⁺ and A⁻.

Since the percentage dissociation of the acid is 0.04%

⇒ The dissociation constant (α) = 0.04/100 = 4 X 10⁻⁴

The concentration of H⁺ in the solution = Cα

According to the question, the concentration (C) = 0.025

Substituting,

[H⁺] = 0.025 X 4 X 10⁻⁴

= 10⁻⁵ moles/L

Hence, the pH = -log (10⁻⁵)

= 5