Chapter 6, Problem 33A

a.

Interpretation Introduction

Interpretation:

The empirical formula that corresponds to each of the molecular formula of sodium peroxide needs to be determined.

Concept Introduction:

A molecular formula tells the actual number of atoms percent in the molecule or compound. The empirical formula is the simplest ratio of number of atoms in the compound.

Answer to Problem 33A

Empirical formula is NaO.

Explanation of Solution

  $\text{Molecular formula =n × empirical formula}$

Given Sodium peroxide Na₂O₂

  $\text{Molecular formula =n × NaO}$, where ‘n’ is 2.

Hence, empirical formula is NaO

b.

Interpretation Introduction

Interpretation:

The empirical formula that corresponds to each of the molecular formula of terephthalic acid needs to be determined.

Concept Introduction:

A molecular formula tells the actual number of atoms percent in the molecule or compound. The empirical formula is the simplest ratio of number of atoms in the compound.

Answer to Problem 33A

Empirical formula is C₄H₃O₂

Explanation of Solution

Terephthalic acid C₈H₆O₄

  $\text{Molecular formula of }Terephthalicacid{C}_8{H}_6{O}_4\text{= n × }{C}_4{H}_3{O}_2$

(where n is 2).

Hence, empirical formula is C₄H₃O₂

C

Interpretation Introduction

Interpretation:

The empirical formula that corresponds to each of the molecular formula of Phenobarbital needs to be determined.

Concept Introduction:

A molecular formula tells the actual number of atoms percent in the molecule or compound. The empirical formula is the simplest ratio of number of atoms in the compound.

Answer to Problem 33A

empirical formula is C₁₂H₁₂N₂O₃

Explanation of Solution

Given: Phenobarbital C₁₂H₁₂N₂O₃

  $\text{Molecular formula =n × }{C}_{12}{H}_{12}{N}_2{O}_3$

(here, n is one because there is no common coefficient for 12,12,2,3)

Hence, empirical formula is C₁₂H₁₂N₂O₃

d.

Interpretation Introduction

Interpretation:

The empirical formula that corresponds to each of the molecular formula of 1,4-dichloro-2-butene needs to be determined.

Concept Introduction:

A molecular formula tells the actual number of atoms percent in the molecule or compound. The empirical formula is the simplest ratio of number of atoms in the compound.

Answer to Problem 33A

Empirical formula is =C₂H₃Cl

Explanation of Solution

Given:

1,4-dichloro-2-butene C₄H₆Cl₂

  ${\text{Molecular formula of 1,4-dichloro-2-butene =n × C}}_{\text{2}}{\text{H}}_{\text{3}}\text{Cl}$

Hence the empirical formula is =C₂H₃Cl