Date: ______________
Name: ___________________
SCH4U Unit 4 Test – Equilibrium V1x
10K
17T
6C
Part A: Multiple Choice (K: 10 Marks)
Please place your answers IN ALL CAPS and in pen in the corresponding boxes below. Choose
the BEST answer.
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Part B: Short Answer (T: 17 Marks, C: 6 Marks)
Thinking and Inquiry:
1. A mixture of 0.100 M NO and 0.500 M H2, are placed in a container. At equilibrium,
there was 0.0238 M of nitrogen in the container.
2NO(g) + 2H2(g) ↔ N2(g) + 2H2O(g)
Determine the equilibrium constant for the reaction. (T/I: 4)
2. A 0.100 mol/L solution of methanoic acid (HCHO2) has a pH of 2.38. Calculate the Ka of
methanoic acid. (T/I: 4)
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Date: ______________
Name: ___________________
3. You place some solid copper(I) bromide CuBr(s) in a beaker of distilled water. You
measure the molar solubility to be 2.0 x 10-4 mol/L at 25°C. What is the Ksp? (T/I: 3)
4. Tap water contains the sulfate ion SO42- at about 0.00400 mol/L. If 10 mL of 0.00100
mol/L BaCl2 is added to 90 mL of tap water, will a precipitate form? Ksp of barium sulfate
is 1.1 x 10-10. (T/I:6)
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Date: ______________
Name: ___________________
Communication:
5. For the equilibrium systems:
i)
2SO2(g) + O2(g) ↔ 2 SO3(g) + heat (exothermic) ->Temperature decrease
ii)
CH4(g) + H2O(g) ↔ CO(g) + 3H2(g) -> Pressure increase by volume decrease
Predict the direction in which each of the systems would be shifted upon application of
the indicated change. Give a brief Le Chatelier explanation for your prediction.
(C:2 each)
6. Explain why a saturated solution of AgCl(aq) would produce a precipitate if you added a
saturated solution of NaCl(aq). (C:2)
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