Chapter U4.78, Problem 7E

(a)

Interpretation Introduction

Interpretation:

The compound having the greatest total mass out of $\text{CuO,}{\text{CuCO}}_{\text{3}}\text{,}\text{and}{\text{Cu}}_{\text{2}}\text{O}$ should be predicted.

Concept Introduction:

The mass of all the atoms that are present in a chemical formula is termed as Molar mass. It is equal to sum of the atomic masses of all atoms that are present in the formula of a compound.

Answer to Problem 7E

  ${\text{Cu}}_{\text{2}}\text{O}$ is a compound having greatest total mass.

Explanation of Solution

CuO is a compound made up of one copper atom and one oxygen atoms thus, the molar mass of CuO is calculated as follows:

  $\begin{array}{c}\text{Molar}\text{mass}\text{of}\text{CuO}=1\times \text{Cu}+1\times \text{O}\\ =\left(1\times 63.546+1\times 15.999\right)\text{g/mol}\\ =79.545\text{g/mol}\end{array}$

CuCO₃ is a compound made up of one copper, one carbon atom and three oxygen atoms thus, the molar mass of CuCO₃ is calculated as follows:

  $\begin{array}{c}\text{Molar}\text{mass}\text{of}{\text{CuCO}}_{\text{3}}=1\times \text{Cu}+1\times \text{C}+3\times \text{O}\\ =\left(1\times 63.546+1\times 12.011+3\times 15.999\right)\text{g/mol}\\ =123.554\text{g/mol}\end{array}$

Cu₂O is a compound made up of 2 copper atom, and one oxygen atoms thus, the molar mass of Cu₂O is calculated as follows:

  $\begin{array}{c}\text{Molar}\text{mass}\text{of}{\text{Cu}}_2\text{O}=2\times \text{Cu}+1\times \text{O}\\ =\left(2\times 63.546+1\times 15.999\right)\text{g/mol}\\ =143.091\text{g/mol}\end{array}$

Thus, ${\text{Cu}}_{\text{2}}\text{O}$ is a compound having greatest total mass.

(b)

Interpretation Introduction

Interpretation:

The compound having greatest mass of copper out of $\text{CuO,}{\text{CuCO}}_{\text{3}}\text{,}\text{and}{\text{Cu}}_{\text{2}}\text{O}$ should be predicted.

Concept Introduction:

The mass of all the atoms that are present in a chemical formula is termed as Molar mass. It is equal to sum of atomic masses of the atoms that are present in a formula of a compound.

Answer to Problem 7E

  ${\text{Cu}}_{\text{2}}\text{O}$ is a compound having greatest mass of copper.

Explanation of Solution

CuO is a compound made up of one copper atom and one oxygen atoms thus, the mass of Cu is calculated as follows:

  $\begin{array}{c}\text{Molar}\text{mass}\text{of}\text{Cu}=1\times \text{Cu}\\ =\left(1\times 63.546\right)\text{g/mol}\\ =63.546\text{g/mol}\end{array}$

CuCO₃ is a compound made up of one copper, one carbon atom and three oxygen atoms thus, the molar mass of Cu in CuCO₃ is calculated as follows:

  $\begin{array}{c}\text{Molar}\text{mass}\text{of}{\text{CuCO}}_{\text{3}}=1\times \text{Cu}\\ =\left(1\times 63.546\right)\text{g/mol}\\ =63.546\text{g/mol}\end{array}$

Cu₂O is a compound made up of 2 copper atom, and one oxygen atoms thus, the molar mass of Cu in Cu₂O is calculated as follows:

  $\begin{array}{c}\text{Molar}\text{mass}\text{of}{\text{Cu}}_2\text{O}=2\times \text{Cu}\\ =\left(2\times 63.546\right)\text{g/mol}\\ =127.092\text{g/mol}\end{array}$

Thus, ${\text{Cu}}_{\text{2}}\text{O}$ is a compound having greatest mass of copper.

(c)

Interpretation Introduction

Interpretation:

The compound representing best deal for the compound should be predicted.

Concept Introduction:

The mass of the atoms that are present in the chemical formula is termed as Molar mass. It is equal to sum of atomic masses of the atoms that are present in a formula of a compound.

Answer to Problem 7E

  ${\text{Cu}}_{\text{2}}\text{O}$ is the compound representing best deal for the company.

Explanation of Solution

The mass of copper in $\text{CuO,}{\text{CuCO}}_{\text{3}}\text{,}\text{and}{\text{Cu}}_{\text{2}}\text{O}$ is 63.546, 63.546, and 127.092 g/mol. As the compound having two copper atoms and one oxygen atom is having larger mass of copper thus the best compound for the extraction of copper in good yield will be given by it. Thus, ${\text{Cu}}_{\text{2}}\text{O}$ is the compound representing best deal for the company.