Chapter 11, Problem 1P

(a)

Interpretation Introduction

Interpretation: The balanced equation for complete oxidation of ethanol should be written and the respiratory quotient should be calculated.

Concept introduction:

The oxidation is addition of oxygen, thus, if any species react with oxygen and it get added to the molecule of that species, it gets oxidized.

Respiratory quotient or RQ is defined as the ratio of volume of carbon dioxide to the volume of the oxygen consumed.

  $RQ=\frac{{\text{CO}}_2\text{ eliminated}}{{\text{O}}_2\text{consumed}}$

Explanation of Solution

The equation for complete oxidation of ethanol is as follows:

  $C_2{H}_{5}OH\left(l\right)+3O_2\left(g\right)\to 2C{O}_2\left(g\right)+3H_{2}O\left(g\right)$

The RQ value is:

  $RQ=\frac{{\text{CO}}_2\text{ eliminated}}{{\text{O}}_2\text{consumed}}$

From the balanced chemical equation,

  $RQ=\frac{2}{3}=0.67$

Hence, respiratory quotient of ethanol is $0.67.$

(b)

Interpretation Introduction

Interpretation: The balanced equation for complete oxidation of acetic acid should be written and the respiratory quotient should be calculated.

Concept introduction:

The oxidation is addition of oxygen, thus, if any species react with oxygen and it get added to the molecule of that species, it get oxidized.

Respiratory quotient or RQ is defined as the ratio of volume of carbon dioxide to the volume of the oxygen consumed.

  $RQ=\frac{{\text{CO}}_2\text{ eliminated}}{{\text{O}}_2\text{consumed}}$

Explanation of Solution

The equation for complete oxidation of acetic acid is:

  $C{H}_{3}COOH\left(l\right)+2O_2\left(g\right)\to 2C{O}_2\left(g\right)+2H_{2}O\left(g\right)$

The RQ value is:

  $RQ=\frac{{\text{CO}}_2\text{ eliminated}}{{\text{O}}_2\text{consumed}}$

From the balanced chemical equation,

  $RQ=\frac{2}{2}=1$

Hence, respiratory quotient of acetic acid is $1$ .

(c)

Interpretation Introduction

Interpretation: The balanced equation for complete oxidation of stearic acid should be written and the respiratory quotient should be calculated.

Concept introduction:

The oxidation is addition of oxygen, thus, if any species react with oxygen and it get added to the molecule of that species, it get oxidized.

Respiratory quotient or RQ is defined as the ratio of volume of carbon dioxide to the volume of the oxygen consumed.

  $RQ=\frac{{\text{CO}}_2\text{ eliminated}}{{\text{O}}_2\text{consumed}}$

Explanation of Solution

The equation for complete oxidation of stearic acid is:

  $C{H}_3{(C{H}_2)}_{16}COOH\left(l\right)+26O_2\left(g\right)\to 18C{O}_2\left(g\right)+18H_{2}O\left(g\right)$

The RQ value is:

  $RQ=\frac{{\text{CO}}_2\text{ eliminated}}{{\text{O}}_2\text{consumed}}$

From the balanced chemical equation,

  $RQ=\frac{18}{26}=0.69$

Hence, respiratory quotient of stearic acid is $0.69.$

(d)

Interpretation Introduction

Interpretation: The balanced equation for complete oxidation of oleic acid should be written and the respiratory quotient should be calculated.

Concept introduction:

The oxidation is addition of oxygen, thus, if any species react with oxygen and it get added to the molecule of that species, it get oxidized.

Respiratory quotient or RQ is defined as the ratio of volume of carbon dioxide to the volume of the oxygen consumed.

  $RQ=\frac{{\text{CO}}_2\text{ eliminated}}{{\text{O}}_2\text{consumed}}$

Explanation of Solution

The equation for complete oxidation of oleic acid is:

  $C{H}_3{(C{H}_2)}_{14}{(CH)}_{2}COOH\left(l\right)+\frac{51}{2}{O}_2\left(g\right)\to 18C{O}_2\left(g\right)+17H_{2}O\left(g\right)$

The RQ value is:

  $RQ=\frac{{\text{CO}}_2\text{ eliminated}}{{\text{O}}_2\text{consumed}}$

From the balanced chemical equation,

  $\begin{array}{c}RQ=\frac{18}{51/2}\\ =\frac{18}{25.5}\\ =0.705\end{array}$

Hence, respiratory quotient of oleic acid is $0.705.$

(e)

Interpretation Introduction

Interpretation: The balanced equation for complete oxidation of linoleic acid should be written and the respiratory quotient should be calculated.

Concept introduction:

The oxidation is addition of oxygen, thus, if any species react with oxygen and it get added to the molecule of that species, it get oxidized.

Respiratory quotient or RQ is defined as the ratio of volume of carbon dioxide to the volume of the oxygen consumed.

  $RQ=\frac{{\text{CO}}_2\text{ eliminated}}{{\text{O}}_2\text{consumed}}$

Explanation of Solution

The equation for complete oxidation of linoleic acid is:

  $C{H}_3{(C{H}_2)}_{12}{(CH)}_{4}COOH\left(l\right)+25O_2\left(g\right)\to 18C{O}_2\left(g\right)+16H_{2}O\left(g\right)$

The RQ value is:

  $RQ=\frac{{\text{CO}}_2\text{ eliminated}}{{\text{O}}_2\text{consumed}}$

From the balanced chemical equation,

  $RQ=\frac{18}{25}=0.72$

Hence, respiratory coefficient of linoleic acid is $\mathrm{0.72.}$