To calculate the percent yield of oxygen, we need to compare the actual yield of oxygen with the theoretical yield.
Step 1: Find the theoretical yield of oxygen.
The molar mass of potassium chlorate (KClO3) is:
- Potassium (K): 39.1 g/mol
- Chlorine (Cl): 35.45 g/mol
- Oxygen (O): 16 g/mol (1 oxygen atom)
So, the molar mass of potassium chlorate is:
(39.1 g/mol) + (35.45 g/mol) + (3 ร 16 g/mol) = 122.55 g/mol
From the balanced chemical equation:
2KClO3 โ 2KCl + 3O2
We can see that 2 moles of potassium chlorate produce 3 moles of oxygen gas. Therefore, the molar ratio is:
2 moles KClO3 : 3 moles O2
For the given mass of potassium chlorate (26.3 g), we need to convert it to moles using the molar mass:
26.3 g รท 122.55 g/mol = 0.214 moles KClO3
Using the molar ratio, we can find the theoretical yield of oxygen:
0.214 moles KClO3 ร (3 moles O2 / 2 moles KClO3) ร (32 g O2 / 1 mol O2) = 10.9 grams O2
Step 2: Calculate the percent yield of oxygen.
To find the percent yield, we divide the actual yield by the theoretical yield and multiply by 100:
Percent Yield = (Actual Yield / Theoretical Yield) ร 100
Given the actual yield of oxygen is 9.45 grams, we can now calculate the percent yield:
Percent Yield = (9.45 g / 10.9 g) ร 100 = 86.7%
Therefore, the percent yield of oxygen is approximately 86.7%.