This question is about the equilibrium 2 SO₂(g) + O₂(g) ⇌ 2 SO(g) Effect Explanation A 0.460 mol sample of SO₂ is mixed with a 0.250 mol sample of O₂ in a sealed container at a constant temperature. When equilibrium is reached at a pressure of 215 kPa, the mixture contains 0.180 mol of SO₂. Calculate the partial pressure, in kPa, of SO₂ in this equilibrium mixture. Partial pressure of SO₂ = kPa A different mixture of SO₂ and O₂ reaches equilibrium at a different temperature. Table 4 shows the partial pressures of the gases at equilibrium. Gas Partial pressure / kPa SO₂ 1.67 x 10² O₂ 1.02 x 10² SO₃ 1.85 x 10² Give an expression for the equilibrium constant (Kc) for this reaction. Calculate the value of the equilibrium constant for this reaction and give its units. Kc Kc = Units What is the effect on the value of Kc if the pressure of this equilibrium mixture is increased at a constant temperature? 2 SO₂(g) + O₂(g) ⇌ 2 SO(g) Tick (✓) one box. The value of Kc increases. stays the same. decreses.

A-Level AQA Chemistry Equilibrium constant (Kp) for Homogeneous Systems: This question is about the equil

This question is about the equilibrium 2 SO₂(g) + O₂(g) ⇌ 2 SO(g) Effect Explanation A 0.460 mol sample of SO₂ is mixed with a 0.250 mol sample of O₂ in a sealed container at a constant temperature - AQA - A-Level Chemistry - Question 5 - 2021 - Paper 1

Question 5

This-question-is-about-the-equilibrium--2-SO₂(g)-+-O₂(g)-⇌-2-SO(g)--Effect--Explanation--A-0.460-mol-sample-of-SO₂-is-mixed-with-a-0.250-mol-sample-of-O₂-in-a-sealed-container-at-a-constant-temperature-AQA-A-Level Chemistry-Question 5-2021-Paper 1.png

This question is about the equilibrium 2 SO₂(g) + O₂(g) ⇌ 2 SO(g) Effect Explanation A 0.460 mol sample of SO₂ is mixed with a 0.250 mol sample of O₂ in a sealed... show full transcript

Worked Solution & Example Answer:This question is about the equilibrium 2 SO₂(g) + O₂(g) ⇌ 2 SO(g) Effect Explanation A 0.460 mol sample of SO₂ is mixed with a 0.250 mol sample of O₂ in a sealed container at a constant temperature - AQA - A-Level Chemistry - Question 5 - 2021 - Paper 1

Step 1

Effect

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Answer

A decrease in overall pressure will decrease the yield of SO.

Step 2

Explanation

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Answer

According to Le Chatelier's Principle, a decrease in pressure shifts the equilibrium to the side with more moles of gas. In this case, the reaction produces 2 moles of SO for every 3 moles of reactants (2 SO₂ + O₂), so lowering the pressure shifts the equilibrium towards the reactants, which decreases the yield of SO.

Step 3

Calculate the partial pressure of SO₂ in this equilibrium mixture

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Answer

To find the partial pressure of SO₂, we first need to determine the moles of all gases at equilibrium. We have:

Total moles = 0.460 mol (SO₂) + 0.250 mol (O₂) - 0.180 mol (SO₂ at equilibrium)
Moles of SO at equilibrium = 0.180 mol

Using the ideal gas equation and knowing that the pressure is 215 kPa:

The total moles at equilibrium = (0.460 - 0.180) + 0.250 = 0.530 mol

Partial pressure of SO₂ can be calculated from:

$P(SO₂) = rac{n(SO₂)}{n_{total}} imes P_{total}$

where:

n(SO₂) = 0.180 mol
n(total) = 0.530 mol (assuming negligible other changes)

Thus, $P(SO₂) = rac{0.180}{0.530} imes 215 ext{ kPa} = 61.1 ext{ kPa}$

Step 4

Give an expression for the equilibrium constant (Kc) for this reaction

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Answer

The expression for the equilibrium constant (Kc) for the reaction is given by:

$K_c = rac{[SO]^2}{[SO_2]^2[O_2]}$

Step 5

Calculate the value of the equilibrium constant for this reaction and give its units

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Answer

From the equilibrium partial pressures given:

$[SO]$ = 1.85 x 10² kPa
$[SO₂]$ = 1.67 x 10² kPa
$[O₂]$ = 1.02 x 10² kPa

Substituting back into the Kc expression gives:

$K_c = rac{(1.85 imes 10^2)^2}{(1.67 imes 10^2)^2 imes (1.02 imes 10^2)}$

Calculating this yields:

$K_c = 7.89$

Units of Kc = kPa $^{-2}$

Step 6

What is the effect on the value of Kc if the pressure of this equilibrium mixture is increased at a constant temperature?

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Answer

The value of Kc stays the same because Kc is only affected by temperature changes within the equilibrium system.

This question is about the equilibrium 2 SO₂(g) + O₂(g) ⇌ 2 SO(g) Effect Explanation A 0.460 mol sample of SO₂ is mixed with a 0.250 mol sample of O₂ in a sealed container at a constant temperature - AQA - A-Level Chemistry - Question 5 - 2021 - Paper 1

Worked Solution & Example Answer:This question is about the equilibrium 2 SO₂(g) + O₂(g) ⇌ 2 SO(g) Effect Explanation A 0.460 mol sample of SO₂ is mixed with a 0.250 mol sample of O₂ in a sealed container at a constant temperature - AQA - A-Level Chemistry - Question 5 - 2021 - Paper 1

Effect

Explanation

Calculate the partial pressure of SO₂ in this equilibrium mixture

Give an expression for the equilibrium constant (Kc) for this reaction

Calculate the value of the equilibrium constant for this reaction and give its units

What is the effect on the value of Kc if the pressure of this equilibrium mixture is increased at a constant temperature?

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