Question

Calculate the concentration of H3O+ in a solution that contains 5.5 × 10-5 M OH- at 25°C. Identify the solution as acidic, basic, or neutral.
a. 1.8 × 10-10 M, acidic
b. 9.2 × 10-1 M, basic
c. 5.5 × 10-10 M, neutral
d. 9.2 × 10-1 M, acidic
e. 1.8 × 10-10 M, basic

Answer 1

Answer:

The correct answer is option (e).

Explanation:

Concentration of hydroxide ions $[OH^-]= 5.5\times 10^{-5} M$

The pOH of the solution is defined as negative logarithm of hydroxide ions of in an aqueous solution.

• Higher the value of pOH more will be the acidic solution.
• Lower the value of pOH more will be the basic solution.
• At value  equal to 7 the solution is said to be neutral.

$pOH=-\log[OH^-]$

$pOH=-\log[5.5\times 10^{-5} M]=4.259$

pH +pOH = 14

pH = 14-pOH

pH=14 - 4.259 = 9.741

The pH of the solution is defined as negative logarithm of hydronium ions of in an aqueous solution.

• Higher the value of pH more will be the basic solution.
• Lower the value of pH more will be the acidic solution.
• At value equal to 7 the solution is said to be neutral.

$pH=-\log[H_3O^+]$

$9.741=-\log[H_3O^+]$

$[H_3O^+]=1.8\times 10^{-10} M$

The solution is basic as pH of the solution is 9.741.