Chapter 10, Problem 167A

Interpretation Introduction

(a)

Interpretation:

The empirical formula of ethylene ${\text{C}}_{\text{2}}{\text{H}}_{\text{4}}$ needs to be determined.

Concept introduction:

Empirical formula is the simplest formula of any organic or inorganic compound that represents the simple ratio of all atoms present in the molecule. It can be calculated with the help of elemental composition of molecule. Certain steps must be used to get the empirical formula:

• Consider mass % as mass in grams and calculate moles of element with the help of molar mass.
• Calculate the moles of each element in least whole number.
• Write the number of each atom as subscript to write the empirical formula.

Answer to Problem 167A

Empirical formula = ${\text{CH}}_{\text{2}}$.

Explanation of Solution

The empirical formula represents the simplest ratio of elements given in the molecular formula. The given molecular formula is ${\text{C}}_{\text{2}}{\text{H}}_{\text{4}}$. Therefore, the simplest ratio that will be empirical formula must be ${\text{CH}}_{\text{2}}$ as it is simplest ratio.

Interpretation Introduction

(b)

Interpretation:

The empirical formula of ascorbic acid ${\text{C}}_{\text{6}}{\text{H}}_{\text{8}}{\text{O}}_{\text{6}}$ needs to be determined.

Concept introduction:

Empirical formula is the simplest formula of any organic or inorganic compound that represents the simple ratio of all atoms present in the molecule. It can be calculated with the help of elemental composition of molecule. Certain steps must be used to get the empirical formula:

• Consider mass % as mass in grams and calculate moles of element with the help of molar mass.
• Calculate the moles of each element in least whole number.
• Write the number of each atom as subscript to write the empirical formula.

Answer to Problem 167A

Empirical formula = ${\text{C}}_3{\text{H}}_4{\text{O}}_{\text{3}}$.

Explanation of Solution

The empirical formula represents the simplest ratio of elements given in the molecular formula. The given molecular formula is ${\text{C}}_{\text{6}}{\text{H}}_{\text{8}}{\text{O}}_{\text{6}}$. Therefore, the simplest ratio that will be empirical formula must be ${\text{C}}_3{\text{H}}_4{\text{O}}_{\text{3}}$ as it is simplest ratio.

Interpretation Introduction

(c)

Interpretation:

The empirical formula of naphthalene ${\text{C}}_{10}{\text{H}}_{\text{8}}$ needs to be determined.

Concept introduction:

Empirical formula is the simplest formula of any organic or inorganic compound that represents the simple ratio of all atoms present in the molecule. It can be calculated with the help of elemental composition of molecule. Certain steps must be used to get the empirical formula:

• Consider mass % as mass in grams and calculate moles of element with the help of molar mass
• Calculate the moles of each element in least whole number
• Write the number of each atom as subscript to write the empirical formula.

Answer to Problem 167A

Empirical formula = ${\text{C}}_5{\text{H}}_4$.

Explanation of Solution

The empirical formula represents the simplest ratio of elements given in the molecular formula. The given molecular formula is ${\text{C}}_{10}{\text{H}}_{\text{8}}$. Therefore, the simplest ratio that will be empirical formula must be ${\text{C}}_5{\text{H}}_4$ as it is simplest ratio.