   Chapter 16, Problem 16.139QP General Chemistry - Standalone boo...

11th Edition
Steven D. Gammon + 7 others
ISBN: 9781305580343

Solutions

Chapter
Section General Chemistry - Standalone boo...

11th Edition
Steven D. Gammon + 7 others
ISBN: 9781305580343
Textbook Problem

Cyanic acid, HOCN, is a weak acid with a Ka value of 3.5 × 10−4 at 25°C. In a 0.293 M solution of the acid, the degree of ionization is 3.5 × 10−2. Calculate the degree of ionization in a 0.293 M solution to which sufficient HCl is added to make it 4.19 × 10−2 M HCl in the given volume.

Interpretation Introduction

Interpretation:

The degree of ionization of 0.293 M solution of cyanic acid with added 4.19×102 M HCl solution has to be calculated

Concept Introduction:

Acid ionization constant Ka :

The ionization of a weak acid HA can be given as follows,

HA(aq)H+(aq)+A-(aq)

The equilibrium expression for the above reaction is given below.

Ka=[H+][A-][HA]

Where,

Ka is acid ionization constant,

[H+]   is concentration of hydrogen ion

[A-]   is concentration of acid anion

[HA] is concentration of the acid

Degree of ionization (α)  is the amount of reactant that undergone ionization in the reaction.

Explanation

To Calculated: The degree of ionization of 0.293 M solution of cyanic acid with added 4.19×102 M HCl solution

Given data:

Cyanic acid, (HOCN) is a weak acid with a Ka value of  3.5×104

The degree of ionization in a 0.293 M solution of Cyanic acid is 3.5×102

Degree of ionization:

The balanced equilibrium equation for the hydrolysis reaction of Cyanic acid, (HOCN) is:

HOCN + H2 H3O+ + OCN-

Set up the equilibrium expression for the above reaction and solve for x.

Ka =(x)(0.0419+x)(0.293x)3.5×104 =(x)(0.0419+x)(0.293x)Assume x is very small compared to 0

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 