Answer:
87.0%
Explanation:
Step 1: Write the balanced reaction
H₂O₂ ⇒ H₂O + 0.5 O₂
Step 2: Calculate the real yield of oxygen, in grams
We have 375 mL (0.375 L) of O₂ at 42 °C (315 K) and 1.52 atm. First, we will calculate the number of moles using the ideal gas equation.
P × V = n × R × T
n = P × V / R × T
n = 1.52 atm × 0.375 L / (0.0821 atm.L/mol.K) × 315 K = 0.0220 mol
The molar mass of oxygen is 32.00 g/mol.
0.0220 mol × 32.00 g/mol = 0.704 g
Step 3: Calculate the theoretical yield of oxygen, in grams
According to the balanced equation, the mass ratio of H₂O₂ to O₂ is 34.01:16.00.
1.72 g H₂O₂ × 16.00 g O₂/34.01 g H₂O₂ = 0.809 g O₂
Step 4: Calculate the percent yield of oxygen
We will use the following expression.
%yield = real yield / theoretical yield × 100%
%yield = 0.704 g / 0.809 g × 100% = 87.0%