Question

RQ of ${ C }_{ 18 }{ H }_{ 32 }{ O }_{ 16 }$ is
(a)0.715
(b)1.00
(c)1.430
(d)2.145

Answer 1

Hint Respiratory quotient, also termed as the respiratory ratio (RQ). It is defined as the volume of carbon dioxide released over the volume of oxygen absorbed during respiration. It’s a dimensionless quantity and is employed in the calculation for basal metabolic rate when estimated from carbon dioxide production to oxygen absorption.

Complete answer:
The respiratory quotient (RQ) is a ratio between ${ CO }_{ 2 }$ produced to ${ O }_{ 2 }$ consumed.
RQ = $\dfrac { { CO }_{ 2 }Eliminated }{ { O }_{ 2 }Consumed }$
Most of the energy sources are food that mostly contains carbon, hydrogen, and oxygen. Examples include fat, carbohydrates, protein, and ethanol. Their metabolism is represented by the equation:
${ C }_{ x }{ H }_{ y }{ O }_{ z }+\left( x+\dfrac { y }{ 4 } -\dfrac { z }{ 2 } \right) { O }_{ 2 }\rightarrow x{ CO }_{ 2 }+\dfrac { y }{ 2 } { H }_{ 2 }O$
-${ C }_{ 18 }{ H }_{ 32 }{ O }_{ 16 }$ is a carbohydrate referred to as raffinose
 For carbohydrate the respiratory quotient after metabolism can be signified by the chemical equation for the oxidation of glucose:
 $ { C }_{ 18 }{ H }_{ 32 }{ O }_{ 16 }+6{ O }_{ 2 }\rightarrow { 6CO }_{ 2 }+6{ H }_{ 2 }O$
Because the gas exchanged in this reaction is same, the respiratory quotient for carbohydrates is: RQ = $\dfrac { 6{ CO }_{ 2 } }{ 6{ O }_{ 2 } } $ = 1.0

Additional information:
The respiratory quotient (RQ) is basically used in the calculations of basal metabolic rate (BMR). It is the ratio of the quantity of carbon dioxide produced by the body to the quantity of oxygen consumed by the body in respiration over a period of time. It depends on the category of respiratory substrate used during respiration. This value also specifies the macronutrients that are being metabolized, as different energy pathways are used for fats, carbohydrates, and proteins.

So, the correct answer is 1.00

Notes: For lipids, the Respiratory Quotient is 0.7, for proteins it is 0.8, and for carbohydrates it is 1.0. Since most of the time, energy consumption is composed of both fats and carbohydrates. Therefore, the approximate respiratory quotient of a mixed diet is 0.8.