Chapter 7, Problem 12CI

(a)

Interpretation Introduction

Interpretation:

The molecular formula of butyric acid needs to be determined.

Concept Introduction :

Molecular formula of a compound can be calculated from its structure from total number of atoms of same element present in it.

(b)

Interpretation Introduction

Interpretation:

The empirical formula of butyric acid needs to be determined.

Concept Introduction :

The empirical formula is simplest ratio of number of atoms present in the molecule.

(c)

Interpretation Introduction

Interpretation:

The mass percent composition of butyric acid needs to be determined.

Concept Introduction :

The mass percent composition means mass percent of each atom present in butyric acid. This can be calculated by taking percent ratio of mass of that atom to mass of butyric acid.

(d)

Interpretation Introduction

Interpretation:

The mass of carbon atom in 0.850 g of butyric acid needs to be determined.

Concept Introduction :

The number of moles can be calculated from mass and molar mass as follows:

  $n=\frac{m}{M}$

Here, m is mass and M is molar mass.

(e)

Interpretation Introduction

Interpretation:

The mass of butyric acid needs to be calculated if the number of oxygen atom is $3.28\times {10}^{23}$ .

Concept Introduction :

In 1 mol of any substance there are $6.022\times {10}^{23}$ units. Also, relation between mass and number of moles is as follows:

  $n=\frac{m}{M}$

Here, m is mass and M is molar mass.

(f)

Interpretation Introduction

Interpretation:

The density of butyric acid is 0.959 g/mL at $20{}^{\text{o}}\text{C}$ . The number of moles of butyric acid in 1.56 mL needs to be determined.

Concept Introduction :

The density is related to mass and volume as follows:

  $d=\frac{m}{V}$

Here, m is mass and V is volume.

Also, number of moles can be calculated from mass and molar mass as follows:

  $n=\frac{m}{M}$

Here, m is mass and M is molar mass.