Answer:
14.544 g of oxygen is needed to produce 120 grams of carbon dioxide.
Explanation:
Animals take in oxygen and breathe out carbon dioxide during cellular respiration. The reaction for the metabolism of the food in the animal body is:

As can be seen from the reaction stoichiometry that:
<u>6 moles of carbon dioxide gas can be produced from 1 mole of oxygen gas in the process of metabolism of glucose.</u>
Also,
Given :
Mass of carbon dioxide gas = 120 g
Molar mass of carbon dioxide gas = 44 g/mol
The formula for the calculation of moles is shown below:

Thus, moles of carbon dioxide are:


As mentioned:
<u>6 moles of carbon dioxide</u> gas can be produced from <u>1 mole of oxygen gas</u> in the process of metabolism of glucose.
<u>1 mole of carbon dioxide</u> gas can be produced from <u>1/6 mole of oxygen gas</u> in the process of metabolism of glucose.
<u>2.7273 mole of carbon dioxide</u> gas can be produced from <u>
moles of oxygen gas</u> in the process of metabolism of glucose.
Thus, moles of oxygen gas needed = 0.4545 moles
Molar mass of oxygen gas = 32 g/mol
The mass of oxygen gas can be find out by using mole formula as:

Thus,



<u>14.544 g of oxygen is needed to produce 120 grams of carbon dioxide.</u>