<u>Answer:</u> The percent yield of the reaction is 91.8 %
<u>Explanation:</u>
To calculate the number of moles, we use the equation:
.....(1)
- <u>For
:</u>
Given mass of
= 4.0 g
Molar mass of
= 63.12 g/mol
Putting values in equation 1, we get:

Given mass of oxygen gas = 10.0 g
Molar mass of oxygen gas = 32 g/mol
Putting values in equation 1, we get:

The chemical equation for the reaction of
and oxygen gas follows:

By Stoichiometry of the reaction:
12 moles of oxygen gas reacts with 2 moles of 
So, 0.3125 moles of oxygen gas will react with =
of 
As, given amount of
is more than the required amount. So, it is considered as an excess reagent.
Thus, oxygen gas is considered as a limiting reagent because it limits the formation of product.
By Stoichiometry of the reaction:
12 moles of oxygen gas produces 5 moles of 
So, 0.3125 moles of oxygen gas will produce =
of water
Now, calculating the mass of
from equation 1, we get:
Molar mass of
= 69.93 g/mol
Moles of
= 0.130 moles
Putting values in equation 1, we get:

To calculate the percentage yield of
, we use the equation:

Experimental yield of
= 8.32 g
Theoretical yield of
= 9.052 g
Putting values in above equation, we get:

Hence, the percent yield of the reaction is 91.8 %