# Calculate the solubility of Zn(CN) 2 at 25°C (a) in pure water and (b) in the presence of 0.10 M Zn(NO 3 ) 2 . K sp for Zn(CN) 2 is 8.0 ×10 −12 .

### Chemistry & Chemical Reactivity

9th Edition
John C. Kotz + 3 others
Publisher: Cengage Learning
ISBN: 9781133949640

Chapter
Section

### Chemistry & Chemical Reactivity

9th Edition
John C. Kotz + 3 others
Publisher: Cengage Learning
ISBN: 9781133949640
Chapter 17.4, Problem 5CYU
Textbook Problem
48 views

## Calculate the solubility of Zn(CN)2 at 25°C (a) in pure water and (b) in the presence of 0.10 M Zn(NO3)2. Ksp for Zn(CN)2 is 8.0 ×10−12.

Interpretation Introduction

Interpretation:

Solubility of salt Zn(CN)2 is to be calculated in pure water at 25°C and this solution already contains (0.10M)ofZn(NO3)2 hence correct solubility should be identified; the corresponding Zn(CN)2 Ksp value has given in the statement.

Concept introduction:

The solubility of a salt is defined as the maximium amount of salt that can be dissolved in definite amount of solvent. It is expressed in moles per liter or grams per liter. Solubility in terms of moles per liter is called molar solubility and is defined as the number of moles of solute (salt) dissolved in per liter of solution.

Solubility product constant Ksp is an equilibrium constant and is defined as the product of the equilibrium concentration of the ions of the salt raised to the power of their coefficients in the balanced chemical equation.

Expression for Ksp of a salt is given as,

AxBy(s)xAy+(aq)+yBx(aq)Ksp=[Ay+]x[Bx]y

Relation between Ksp and s is derived as follows,

EquationAxByxAy++yBxInitial(M)00Change(M)+xs+ysEquilibrium(M)xsys

Ksp=[Ay+]x[Bx]yKsp=(xs)x(ys)y=xxyy(s)x+y

Rearrange the expression for s .

(s)x+y=Kspxxyy=(Kspxxyy)1/(x+y)

Here,

• x is the coefficient of cation A+y
• y is the coefficient of anion Bx
• s is the molar solubility

Ksp is calculated by using molar solubility of the salt.

### Explanation of Solution

Analyzing for statement (a)

Solubility of salt Zn(CN)2 in pure water is to be calculated as follows,

Given:

The value of solubility product Ksp of Zn(CN)2 is 8.0×1012 at  25°C

Zn(CN)2 when dissolved in water dissociates as ,

Zn(CN)2(s) Zn2+(aq)+ 2CN-(aq)

The ICE table is as follows,

EquationZn(CN)2Zn2++2CN-Initial (M)00Change (M)+s2sEquilibrium (M) s2s

Ksp=[Zn2+][CN-]2

Substitute s for [Zn2+] and for [CN-]2 .

Ksp=s×s

Here,

• Ksp is solubility product constant
• s is solubility

Ksp=s2

Rearrange the above expression.

s=Ksp2

Again, substitute 8.0×1012 for Ksp .

s=8.0×10122= 2.82×10-6M

Analyzing for statement (b)

Let us consider the solubility of (S)

Given:

The value of solubility product Ksp of Zn(CN)2 is 8.0×1012 at 25°C in the Zn(NO3)2 0.1 M solution.

Zn(CN)2 when dissolved in water dissociates as ,

Zn(CN)2(s) Zn2+(aq)+ 2CN-(aq)

The ICE table is as follows,

EquationZn(CN)2Zn2++2CN-Initial (M)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
What are the moral implications of using ergogenic aids?

Understanding Nutrition (MindTap Course List)

A basketball star covers 2.80 m horizontally in a jump to dunk the ball (Fig. P4.12a). His motion through space...

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

What is the difference between sand spits and bay mouth bars?

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

In what years did per capita fish consumption decrease?

Environmental Science (MindTap Course List)

Today, famine is most often a result of global food shortage drought social causes such as war flood

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