During oxidation of certain food substances, the respiratory quotient was found to be 0.718

here are the solutions to the questions:

22. The apparatus shown demonstrates the decomposition of hydrogen peroxide by the enzyme catalase.

a) Name the gas X.
Hydrogen peroxide decomposes into water and oxygen gas. Therefore, Gas X is oxygen.

$$\boxed{\text{Oxygen}}$$

b) Write down a word equation for the reaction which produces the gas.
The enzyme catalase speeds up the breakdown of hydrogen peroxide into water and oxygen.

$$\boxed{\text{Hydrogen peroxide} \xrightarrow{\text{Catalase}} \text{Water} + \text{Oxygen}}$$

c) Where in human body does this type of reaction occur?
Catalase is an enzyme found in many cells, particularly in organelles called peroxisomes, which are abundant in the liver and kidneys.

$$\boxed{\text{Liver cells (or peroxisomes)}}$$

23. The question "During oxidation of certain food substances, the respiratory quotient was found to be 0.718" is incomplete. Please provide the full question for me to solve it.