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Name:
Equilibrium 2
Created By:
V. Gokal
Max Time:
5 mins
Select an option for each question and click Submit
1. A gas X is placed in a sealed container at t = 0 s. The gas decomposes into gases Y and Z. A chemical equilibrium between the three gases is reached at t = tx.
The following graph of concentration versus time shows the changes that occurred during the reaction:
3X ↔ 2Y + Z
X ↔ Y + Z
X ↔ 2Y + Z
2X ↔ 2Y + Z
2. A mixture of H
2
(g) and I
2
(g) is sealed in a gas syringe. The mixture is then allowed to reach equilibrium at a constant temperature according to the equation:
What will happen to the
concentration
and
yield
of HI if the piston is moved inwards while the temperature remains constant?
Increases / Decreases
Decreases / Stays the same
Decreases / Increases
Increases / Stays the same
3. An equilibrium in a closed container is represented by the following equation:
N
2
(g) + 3H
2
(g) ↔ 2NH
2
(g) ΔH < 0
Which one of the following actions will affect both the value of Kc and the concentration of ammonia present at equilibrium?
Adding a suitable catalyst
Reducing the temperature
Increasing the mass of nitrogen
Increasing the pressure at a constant temperature
4. Consider the equation below:
CaO(s) + SO
2
(g) ↔ CaSO(s)
If the equilibrium concentration of SO
2
(g) at 25°C is equal to x mol.dm
-3
the value of the equilibrium constant at this temperature will be equal to:
x
x
2
1
/
x
2
/
x
2
5. Consider the following chemical reaction at equilibrium in a closed system:
2CO(g) + O
2
(g) ↔ 2CO
2
(g)
A catalyst is added to the system at constant temperature. What effect will this have on the
Kc
value and on the
yield
of CO
2
respectively?
Increases / Decreases
Unchanged / Unchanged
Unchanged / Increases
Decreases / Increases
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