<u>Answer:</u> The percent yield of oxygen gas is 67.53 %.
<u>Explanation:</u>
To calculate the number of moles, we use the equation:
.....(1)
Given mass of water = 17.0 g
Molar mass of water = 18 g/mol
Putting values in equation 1, we get:

For the given chemical equation:

By Stoichiometry of the reaction:
2 moles of water produces 1 mole of oxygen gas
So, 0.944 moles of water will produce =
of oxygen gas
Now, calculating the mass of oxygen gas from equation 1, we get:
Molar mass of oxygen gas = 32 g/mol
Moles of oxygen gas = 0.472 moles
Putting values in equation 1, we get:

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

Experimental yield of oxygen gas = 10.2 g
Theoretical yield of oxygen gas = 15.104 g
Putting values in above equation, we get:

Hence, the percent yield of oxygen gas is 67.53 %.