GATE 2023 BT – Question 46
The following reaction represents biomass synthesis from hexadecane: $C_{16}H_{34}+12.5O_2+2.13NH_3\to10.6CH_{1.66}O_{0.27}N_{0.27}+5.37CO_2+11.4H_2O$. The value of respiratory quotient (rounded off to two decimal places) is ___________.
Practise this question in The GATE Grind →
Show answer and explanation
Correct answer: 0.42 to 0.44
Explanation
The **respiratory quotient** is the ratio of the moles of $CO_2$ produced to the moles of $O_2$ consumed:
$$RQ=\frac{n_{CO_2}}{n_{O_2}} .$$
From the reaction, 5.37 mol of $CO_2$ are produced and 12.5 mol of $O_2$ are consumed:
$$RQ=\frac{5.37}{12.5}=0.4296\approx\mathbf{0.43}.$$
(A low value is expected for a very reduced substrate such as hexadecane, because much of its carbon goes into biomass.)