Chapter 3, Problem 3.124P

(a)

Interpretation Introduction

Interpretation:

The number of moles present in $0.588\text{ g}$ of ammonium bromide is to be calculated.

Concept introduction:

The number of moles is calculated by the formula:

  $\text{Number of moles}=\frac{\text{given mass of sample}\left(\text{g}\right)}{\text{molecular mass (g/mol)}}$        (1)

The formula to calculate mass is as follows:

  $\text{Mass of a given sample}\left(\text{g}\right)=\left(\text{molecular mass}\left(\text{g/mol}\right)\right)\left(\text{number of moles}\right)$        (2)

(b)

Interpretation Introduction

Interpretation:

The number of potassium ions in $88.5\text{ g}$ of potassium nitrate is to be calculated.

Concept introduction:

The number of moles is calculated by the formula :

  $\text{Number of moles}=\frac{\text{given mass of sample}\left(\text{g}\right)}{\text{molecular mass (g/mol)}}$        (1)

The formula to calculate mass from moles is as follows:

  $\text{Mass of a given sample}\left(\text{g}\right)=\left(\text{molecular mass}\left(\text{g/mol}\right)\right)\left(\text{number of moles}\right)$        (2)

(c)

Interpretation Introduction

Interpretation:

The mass of $5.85\text{ mol}$ glycerol is to be calculated.

Concept introduction:

The formula to calculate the moles is as follows:

  $\text{Number of moles}=\frac{\text{given mass of sample}\left(\text{g}\right)}{\text{molecular mass (g/mol)}}$        (1)

The formula to calculate mass from moles is as follows:

  $\text{Mass of a given sample}\left(\text{g}\right)=\left(\text{molecular mass}\left(\text{g/mol}\right)\right)\left(\text{number of moles}\right)$        (2)

(d)

Interpretation Introduction

Interpretation:

The volume of $2.85\text{ mol}$ chloroform is to be calculated.

Concept introduction:

The number of moles is calculated by the formula:

  $\text{Number of moles}=\frac{\text{given mass of sample}\left(\text{g}\right)}{\text{molecular mass (g/mol)}}$        (1)

The relation between density, mass and volume is as follows:

  $\text{Density}\left(\text{g/mL}\right)\text{ =}\frac{\text{Mass}\left(\text{g}\right)}{\text{Volume}\left(\text{mL}\right)}$        (2)

(e)

Interpretation Introduction

Interpretation:

The number of sodium ions present in $\text{2}\text{.11 mol}$ sodium carbonate is to be calculated.

Concept introduction:

The number of moles is calculated by the formula:

  $\text{Number of moles}=\frac{\text{given mass of sample}\left(\text{g}\right)}{\text{molecular mass (g/mol)}}$        (1)

(f)

Interpretation Introduction

Interpretation:

The number of atoms in $\text{25}\text{.0 μg}$ cadmium is to be calculated.

Concept introduction:

The symbol and molar mass of cadmium is $\text{Cd}$ $112.4\text{ g/mol}$ respectively.

The number of moles is calculated by the formula:

  $\text{Number of moles}=\frac{\text{given mass of sample}\left(\text{g}\right)}{\text{molecular mass (g/mol)}}$        (1)

The formula to evaluate the number of atoms is as follows:

  $\text{Number of atoms}=\left(\text{number of moles}\right)\left(6.022\times {10}^{23}\right)$        (3)

The conversion factor for converting $\text{μg}$ to $\text{g}$ is as follows:

$1\text{ μg}={10}^{-6}\text{g}$

(g)

Interpretation Introduction

Interpretation:

The number of atoms in $\text{0}\text{.0015 mol}$ of fluorine gas is to be calculated.

Concept introduction:

The number of moles is calculated by the formula:

  $\text{Number of moles}=\frac{\text{given mass of sample}\left(\text{g}\right)}{\text{molecular mass (g/mol)}}$        (1)