Chapter 10, Problem 83A

(a)

Interpretation Introduction

Interpretation: The error in the given statement needs to be identified.

Concept Introduction: According to Avogadro’s law, in 1 mol of a substance there are

  $6.022\times {10}^{23}$ units of that substance.

Explanation of Solution

The given statement is “one mole of any substance contains the same number of atoms”. This statement is not correct as one mole of any element contains the same number of atoms. The number of units of a substance present in 1 mol of a substance is the same. There are different types of units (representative particles) for a different substance. For elements, it is atoms; for molecules, it is molecules and for compounds, it is formula units.

Thus, the correct statement would be “one mole of any substance contains the same number of units of that substance.

(b)

Interpretation Introduction

Interpretation: The error in the given statement needs to be identified.

Concept Introduction: According to Avogadro’s law, in 1 mol of a substance there are

  $6.022\times {10}^{23}$ units of that substance.

Explanation of Solution

The given statement is “a mole and a molecule of a substance are identical in amount”. The statement is wrong because for a substance or molecule, in 1 mol there are $6.022\times {10}^{23}$ number of molecules. The correct statement would be, in 1 mol of a molecule, there are $6.022\times {10}^{23}$ number of molecules.

(c)

Interpretation Introduction

Interpretation: The error in the given statement needs to be identified.

Concept Introduction: According to Avogadro’s law, in 1 mol of a substance there are

  $6.022\times {10}^{23}$ units of that substance.

Explanation of Solution

The given statement is “one molar mass of ${\text{CO}}_{\text{2}}$ contains Avogadro’s number of atoms.” According to Avogadro’s law, in 1 mol of ${\text{CO}}_{\text{2}}$ there are $6.022\times {10}^{23}$ number of ${\text{CO}}_{\text{2}}$ molecules. Here, $6.022\times {10}^{23}$ is Avogadro’s number. Here, the molar mass of carbon dioxide gives the mass in 1 mol or mass of $6.022\times {10}^{23}$ number of ${\text{CO}}_{\text{2}}$ molecules. Therefore, the given statement is wrong.

The correct statement would be one mole of ${\text{CO}}_{\text{2}}$ contains Avogadro’s number of ${\text{CO}}_{\text{2}}$ molecules.