Chapter 3, Problem 3.34P

(a)

Interpretation Introduction

Interpretation:

Whether from the number of moles of each type of atom in a given sample of the compound the molecular formula can be obtained or not is to be explained. Also, a road map is to be drawn if the molecular formula can be obtained.

Concept introduction:

The molecular formula describes the chemical symbols and numeric subscripts indicating the exact number of atoms comprising the whole chemical compound. The molecular formula does not suggest about the chemical bonding of that particular compound.

The empirical formula describes the simplest whole-integer ratio of atoms of the chemical compound. The molecular formula can either be similar to empirical formula otherwise it can be the multiple of the empirical formula.

(b)

Interpretation Introduction

Interpretation:

Whether from the mass $\%$ of each element and the total number of atoms in a molecule of the compound the molecular formula can be obtained or not is to be explained. Also, a road map is to be drawn if the molecular formula can be obtained.

Concept introduction:

The molecular formula describes the chemical symbols and numeric subscripts indicating the exact number of atoms comprising the whole chemical compound. The molecular formula does not suggest about the chemical bonding of that particular compound.

The empirical formula describes the simplest whole-integer ratio of atoms of the chemical compound. The molecular formula can either be similar to empirical formula otherwise it can be the multiple of the empirical formula.

The expression to calculate the mass of an element from the mass $\%$ is as follows:

  $\text{Mass of element}=\left(\frac{\left(\text{Mass }\%\right)\left(\text{Mass of compound}\right)}{100}\right)$

The expression for the calculation of the number of moles is as follows:

  $\text{Moles}\text{of}\text{element}=\left(\text{given mass}\left(\text{g}\right)\text{of element}\right)\left(\frac{1\text{ mol element}}{\text{molecular mass}\left(\text{g}\right)}\right)$

(c)

Interpretation Introduction

Interpretation:

Whether from the mass $\%$ of each element and the number of atoms of one element in a molecule of the compound the molecular formula can be obtained or not is to be explained. Also, a road map is to be drawn if the molecular formula can be obtained.

Concept introduction:

The molecular formula describes the chemical symbols and numeric subscripts indicating the exact number of atoms comprising the whole chemical compound. The molecular formula does not suggest about the chemical bonding of that particular compound.

The empirical formula describes the simplest whole-integer ratio of atoms of the chemical compound. The molecular formula can either be similar to empirical formula otherwise it can be the multiple of the empirical formula.

The expression to calculate the mass of an element from the mass $\%$ is as follows:

  $\text{Mass of element}=\left(\frac{\left(\text{Mass }\%\right)\left(\text{Mass of compound}\right)}{100}\right)$

The expression for the calculation of the number of moles is as follows:

  $\text{Moles}\text{of}\text{element}=\left(\text{given mass}\left(\text{g}\right)\text{of element}\right)\left(\frac{1\text{ mol element}}{\text{molecular mass}\left(\text{g}\right)}\right)$

(d)

Interpretation Introduction

Interpretation:

Whether from the empirical formula and mass $\%$ of each element the molecular formula can be obtained or not is to be explained. Also, a road map is to be drawn if the molecular formula can be obtained.

Concept introduction:

The molecular formula describes the chemical symbols and numeric subscripts indicating the exact number of atoms comprising the whole chemical compound. The molecular formula does not suggest about the chemical bonding of that particular compound.

The empirical formula describes the simplest whole-integer ratio of atoms of the chemical compound. The molecular formula can either be similar to empirical formula otherwise it can be the multiple of the empirical formula.

(e)

Interpretation Introduction

Interpretation:

Whether from the structural formula the molecular formula can be obtained or not is to be explained. Also, a road map is to be drawn if the molecular formula can be obtained.

Concept introduction:

The molecular formula describes the chemical symbols and numeric subscripts indicating the exact number of atoms comprising the whole chemical compound. The molecular formula does not suggest about the chemical bonding of that particular compound.

The empirical formula describes the simplest whole-integer ratio of atoms of the chemical compound. The molecular formula can either be similar to empirical formula otherwise it can be the multiple of the empirical formula.