Question

Calculate the [OH) in units of M of an aqueous solution of bleach which has a [H₃O⁺] = 4.8 x 10-12 M.

A. 4.8 x 10⁺² M.
B. 2.1 x 10⁻³ M
C. 4.8 x 10⁻¹² M
D. 1.0 x 10⁻¹⁴ M
E. 2.1 x 10⁻²⁵ M
F. 4.8 x 10⁻²⁶ M

Answer 1

The concentration of hydroxide ions ([OH-]) in an aqueous solution of bleach with a given hydronium ion concentration ([H3O+]) of 4.8 x 10^-12 M is calculated using the water ion product constant, and the resulting concentration of OH- is 2.1 x 10^-3 M. Therefore, the correct option from the provided choices is B. 2.1 × 10-3 M.

Step-by-step explanation:

To calculate the concentration of hydroxide ions ([OH-]) in an aqueous solution of bleach with a known hydronium ion concentration ([H3O+]), we use the ion product constant for water (Kw). The product of the concentrations of the hydronium ions and hydroxide ions always equals 1.0 × 10-14 at 25°C. The formula to find [OH-] is [OH-] = Kw / [H3O+].

Given that the concentration of hydronium ions in the solution is 4.8 × 10-12 M, we can solve for [OH-] as follows:

[OH-] = (1.0 × 10-14) / (4.8 × 10-12)

Performing the calculation gives us a concentration of hydroxide ions equal to:

[OH-] = 2.1 × 10-3 M

Therefore, the correct option from the provided choices is B. 2.1 × 10-3 M.