If glucose is incompletely oxidized to ethyl alcohol in the absence...

The chemical equation for the incomplete oxidation of glucose to ethyl alcohol in the absence of oxygen (anaerobic respiration) is given by:

$C_6H_{12}O_6 \rightarrow 2C_2H_5OH + 2CO_2 + \text{Energy}$

The respiratory quotient (RQ) is the ratio of the volume of carbon dioxide evolved to the volume of oxygen consumed during respiration.

$RQ = \dfrac{\text{Volume of } CO_2 \text{ evolved}}{\text{Volume of } O_2 \text{ consumed}}$

In this process, $2$ molecules of $CO_2$ are evolved while $0$ molecules of $O_2$ are consumed.

$RQ = \dfrac{2}{0} = \infty$

Thus, the RQ is infinite.

Answer: infinite