   Chapter 16, Problem 52PS

Chapter
Section
Textbook Problem

The ionizations constant of a very weak acid, HA is 4.0 × 10 − 9 .Calculate the equilibrium concentrations of H 3 O + , A‒ and HA in a 0.040M solution of the acid.

Interpretation Introduction

Interpretation:

The equilibrium concentrations of H3O+,A- and HA in a 0.040M solution of the acid has to be calculated.

Concept introduction:

Equilibrium constants:

The equilibrium constant is used to quantitative measurement of the strength of the acid and bases in the water.

Ka is acid constant for equilibrium reactions.

HA + H2OH3O++ A-Ka[H3O+][A-][HA]

Kb is base constant for equilibrium reaction.

BOH + H2OB++ OH-Ka[B+][OH-][BOH]

Explanation

The equation for the reaction of a weak acid with water and its equilibrium constant expression are

HA + H2A- + H3O+Ka(Weak acid)= [A-][H3O+][HA]

Enter the ICR table the concentrations before equilibrium is established, the change that occurs as the reaction proceeds to equilibrium and the concentrations when equilibrium has been achieved.

HA     + H2A- + H3O+I         0.040M          --         --        --C          -x                 --       + x     + xE       (0.040 - x)      --          x        x

The Ka of the acetic acid is 4.0×10-9

Ka(Weak acid)= [A-][H3O+][HA] = 4

Still sussing out bartleby?

Check out a sample textbook solution.

See a sample solution

The Solution to Your Study Problems

Bartleby provides explanations to thousands of textbook problems written by our experts, many with advanced degrees!

Get Started 