   Chapter 21, Problem 29E

Chapter
Section
Textbook Problem

# When 6 M ammonia is added gradually to aqueous copper(II) nitrate, a white precipitate forms. The precipitate dissolves as more 6 M ammonia is added. Write balanced equations to explain these observations. [Hint: Cu2+ reacts with NH3 to form Cu(NH3)42+.]

Interpretation Introduction

Interpretation: It is given that, when 6 M ammonia is added gradually to aqueous copper (II) nitrate, a white precipitate forms. The precipitate dissolves as more 6 M ammonia is added. The balanced equations to explain these observations are to be stated.

Concept introduction: In a balanced reaction, number of atoms is same on both sides of the chemical equation.

Explanation

Explanation

Weak base ammonia (NH3) gives hydroxide ion (OH) in the aqueous solution. The reaction is,

NH3(aq)+H2O(l)NH4+(aq)+OH(aq)

This reaction is already in its balanced form.

Copper (II) nitrate contains Cu2+ ion that reacts with hydroxide ion to produce a white precipitate of copper hydroxide Cu(OH)2(s) . The reaction is,

Cu2+(aq)+OH(aq)Cu(OH)2(s)

The number of oxygen and hydrogen atoms, present on either side of the reaction, is not balanced. The coefficient 2 is added to OH . This balances the number of oxygen and hydrogen atoms. The balanced equation thus obtained is,

Cu2+(aq)+2OH(aq)Cu(OH)2(s)

The precipitate dissolves as more ammonia is added

### 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 