<u>Answer:</u> The amount of carbon dioxide formed in the reaction is 5.663 grams
<u>Explanation:</u>
To calculate the number of moles, we use the equation:
.....(1)
Given mass of oxygen gas = 8 g
Molar mass of oxygen gas = 32 g/mol
Putting values in equation 1, we get:

For the given chemical equation:

By Stoichiometry of the reaction:
7 moles of oxygen gas produces 4 moles of carbon dioxide
So, 0.25 moles of oxygen gas will produce =
of carbon dioxide
Now, calculating the mass of carbon dioxide from equation 1, we get:
Molar mass of carbon dioxide = 44 g/mol
Moles of carbon dioxide = 0.143 moles
Putting values in equation 1, we get:

To calculate the experimental yield of carbon dioxide, we use the equation:

Percentage yield of carbon dioxide = 90 %
Theoretical yield of carbon dioxide = 6.292 g
Putting values in above equation, we get:

Hence, the amount of carbon dioxide formed in the reaction is 5.663 grams