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The reaction for the oxidation of sulfur dioxide, SO2, is shown below - VCE - SSCE Chemistry - Question 8 - 2021 - Paper 1
Question 8
The reaction for the oxidation of sulfur dioxide, SO2, is shown below. 2SO2(g) + O2(g) ⇌ 2SO3(g) ΔH = -197 kJ mol⁻¹ 1. 00 mol of SO2 and 1.00 mol of oxygen, O2, ar... show full transcript
Worked Solution & Example Answer:The reaction for the oxidation of sulfur dioxide, SO2, is shown below - VCE - SSCE Chemistry - Question 8 - 2021 - Paper 1
Step 1
Calculate Kc: 1.00 mol of SO2 and 1.00 mol of O2 in a 3.00 L container.
Answer
To find the equilibrium constant, Kc, we first need to determine the concentrations of all species at equilibrium.
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Initial concentrations:
[SO2] = 1.00 mol / 3.00 L = 0.33 M,
[O2] = 1.00 mol / 3.00 L = 0.33 M,
[SO3] = 0 M.
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Change in concentrations: Let x be the amount of SO2 that reacts.
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At equilibrium:
- [SO2] = 0.33 - x,
- [O2] = 0.33 - x,
- [SO3] = 2x.
Given that the mass of SO3 at equilibrium is 20.0 g, we convert this to moles: .
This means that at equilibrium, [SO3] = 0.25 mol / 3.00 L = 0.083 M.
Substituting this into the equilibrium relationship:
- From the stoichiometry of the reaction, we have: [SO3] = 2x, thus: .
Now substituting into the equilibrium concentrations:
- [SO2] = 0.33 - 0.125 = 0.205 M,
- [O2] = 0.33 - 0.125 = 0.205 M.
Finally, we can determine Kc: .
Step 2
Draw the Maxwell-Boltzmann distribution curve for SO3.
Answer
To draw the Maxwell-Boltzmann distribution curve for SO3 at a significantly lower temperature, follow these guidelines:
- The peak of the curve should be shifted to the left compared to that of SO2.
- The height of the new peak should be lower, indicating fewer particles have higher kinetic energy due to the lower temperature.
This results in a curve that is broader and shifted leftward, emphasizing the lower average kinetic energy of the SO3 molecules at the lower temperature.