ANSWER
The percentage impurity is 64.875%
Step-by-step explanation
Given that;
The volume of the impure oxygen is 64 liters
The mass of water is 36.8 grams
Follow the steps below to find the percentage impurity
Step 1; Find the moles of water using the below formula
Recall, that the molar mass of water is 18.0 g/mol
The moles of water is 2.04 moles
Step 2; Find the moles of oxygen using stoichiometry ratio
In the reaction, 1 mole of oxygen gives 2 moles of water
Let x represents the number of moles of oxygen
The mole of oxygen is 1.02 moles
Step 3; Find the volume of oxygen using a stoichiometry ratio
Recall, that 1 mole of O2 at STP is equivalent to 22.4 L/mol
Let x represents the volume of oxygen
The volume of oxygen gas is 22.848L
Step 4; Find the percentage impurity of oxygen using the below formula
Therefore, the percentage impurity is 64.875%