   # Consider 1000. mL of a 1.00 × 10 −4 -M solution of a certain acid HA that has a K a value equal to 1.00 × 10 −4 . How much water was added or removed (by evaporation) so that a solution remains in which 25.0% of HA is dissociated at equilibrium? Assume that HA is nonvolatile. ### Chemistry: An Atoms First Approach

2nd Edition
Steven S. Zumdahl + 1 other
Publisher: Cengage Learning
ISBN: 9781305079243

#### Solutions

Chapter
Section ### Chemistry: An Atoms First Approach

2nd Edition
Steven S. Zumdahl + 1 other
Publisher: Cengage Learning
ISBN: 9781305079243
Chapter 13, Problem 179CP
Textbook Problem
5 views

## Consider 1000. mL of a 1.00 × 10−4-M solution of a certain acid HA that has a Ka value equal to 1.00 × 10−4. How much water was added or removed (by evaporation) so that a solution remains in which 25.0% of HA is dissociated at equilibrium? Assume that HA is nonvolatile.

Interpretation Introduction

Interpretation: The value of Ka , volume and concentration of certain acid HA is given. The volume of water added or removed is to be calculated for the given condition.

Concept introduction: The equilibrium constant Ka is the ratio of product of equilibrium concentrations of product to the equilibrium concentration of reactant acid.

The number of moles is calculated using the formula,

Numberofmoles=Volume×Concentration

### Explanation of Solution

Explanation

To determine: The volume of water added or evaporated.

The total number of moles of acid is 1.0×104mol_ .

Given

Volume of HA is 1000mL .

The concentration of HA is 1.0×104M .

The value of Ka is 1.0×104 .

Formula

The number of moles is calculated using the formula,

Numberofmoles=Volume×Concentration

Substitute the values of volume and concentration of HA in the above equation.

Numberofmoles=Volume×Concentration=1.0×104mol/L×1.0L=1.0×104mol_

The number of moles of H+ is 2.5×105mol_ .

The number of moles of A is 2.5×105mol_ .

The number of moles of HA is 7.50×105mol_ .

The reaction of dissociation of HA is,

HAH++A

It is given that 25% of acid is dissociated. It means that 25% of product is formed and 75% of acid is left.

The number of moles of reactant and product is calculated using the formula,

Numberofmoles=Amountofreactantorproduct×Totalmoles (1)

Substitute the percent of production of H+ and total calculated moles in the above equation.

NumberofmolesofH+=Amountofreactantorproduct×Totalmoles=25100×1.0×104mol=2.5×105mol_

Substitute the percent of production of A and total calculated moles in the equation (1).

NumberofmolesofA=Amountofreactantorproduct×Totalmoles=25100×1.0×104mol=2.5×105mol_

Substitute the percent of production of HA and total calculated moles in the equation (1).

NumberofmolesofHA=Amountofreactantorproduct×Totalmoles=75100×1.0×104mol=7

### 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

Find more solutions based on key concepts
The dietary monosaccharides include. sucrose, glucose, and lactose fructose, glucose, and galactose galactose, ...

Nutrition: Concepts and Controversies - Standalone book (MindTap Course List)

What are genomes?

Human Heredity: Principles and Issues (MindTap Course List)

Why is the following situation impossible? The centers of two homogeneous spheres are 1.00 m apart. The spheres...

Physics for Scientists and Engineers, Technology Update (No access codes included)

How can solar flares affect Earth?

Foundations of Astronomy (MindTap Course List)

How can wind-driven horizontal movement of water induce vertical movement in surface water?

Oceanography: An Invitation To Marine Science, Loose-leaf Versin 