Searching for some practice questions on HSC Chemistry Module 5: Equilibrium and Acid Reactions? 

Look no further! 

We know how tricky it is to find practice questions on new concepts such as Ksp that were not in the previous syllabus.

So, we’ve collected and composed 20 practice questions that cover all 17 learning dot points of HSC Chemistry Equilibrium and Acid Reactions. 

If you need a quick recap of Module 5, make sure you check out our guide here on what Equilibrium and Acid Reactions is all about PLUS how to get a Band 6 in it!

What are you waiting for? Let’s get grinding! 

Static and Dynamic Equilibrium 
Factors that Affect Equilibrium 
Solution Equilibria 

Static and Dynamic Equilibrium 

Question 1

Complete the table below (11 marks)

 

(L1.1: Conduct practical investigations to analyse the reversibility of chemical reactions, for example: Cobalt(II) chloride hydrated and dehydrated, Iron(III) nitrate and potassium thiocyanate, Burning magnesium, Burning steel wool)

Question 2

State whether the following reactions are static or dynamic equilibrium reactions and provide relevant chemical equations. (6 marks)

a) The combustion of magnesium 

b) Iron (III) hexahydrate and KSCN 

c) Nitrogen dioxide and carbon oxide 

 

(L1.2: Model static and dynamic equilibrium and analyse the differences between open and closed systems)

Question 3

Can dynamic equilibriums proceed in open systems? Explain why or why not. (3 marks) 

 

(L1.2: Model static and dynamic equilibrium and analyse the differences between open and closed systems)

Question 4

Explain the relationship between enthalpy and entropy during a combustion reaction and a photosynthetic reaction. (4 marks)

 

(L1.3: Analyse examples of non-equilibrium systems in terms of the effect of entropy and enthalpy, for example: Combustion reactions, Photosynthesis)

Question 5

Explain the three ways the collision theory accounts for reaction rate of chemical equilibrium reactions. (3 marks)

 

(L1.4: Investigate the relationship between collision theory and reaction rate in order to analyse chemical equilibrium reactions)

Factors that Affect Equilibrium 

Question 6

Account for the effect of increased temperature and increased volume on the reaction between nitrogen dioxide and dinitrogen tetraoxide using the Le Chatelier’s principle. (4 marks)

 

(L2.1: Investigate the effects of temperature, concentration, volume and/or pressure on a system at equilibrium and explain how Le Chatelier’s principle can be used to predict such effects)

Question 7

Using the Le Chatelier’s principle, explain how the addition of NaCl can be used to produce more Fe3+ and SCNions in the following reaction. (4 marks)

Image source

 

(L2.1: Investigate the effects of temperature, concentration, volume and/or pressure on a system at equilibrium and explain how Le Chatelier’s principle can be used to predict such effects)

Question 8

Using the Le Chatelier’s principle, deduce how we can increase the yield of Co(H2O)62+ by temperature, concentration and pressure. The chemical reaction is as follows: 

Image source

 

(L2.1: Investigate the effects of temperature, concentration, volume and/or pressure on a system at equilibrium and explain how Le Chatelier’s principle can be used to predict such effects)

Question 9

Consider the reaction in question 8. Explain whether the addition of NaCl increases the production of its products using the collision theory. (4 marks)

 

(L2.2: Explain the overall observations about equilibrium in terms of the collision theory) 

Question 10

Predict the most likely position of the equilibrium in the following conditions. (4 marks)

a) Low activation energy in forward reaction but high activation energy in reverse reaction 

b) High activation energy in forward reaction but low activation energy in reverse reaction 

c) Negative heat of reaction within high temperatures 

d) Negative heat of reaction within low temperatures 

 

(L2.3: Examine how the activation energy and heat of reaction affect the position of equilibrium) 

Question 11

Write the equilibrium expression for each of the reactions below (3 marks): 

 

(L3.1: Deduce the equilibrium expression (in terms of Keq) for homogeneous reactions occurring in solution) 

Question 12

0.5 moles of N2 gas was added to a 10L chamber with O2 gas which produced 0.3 moles of NO2 gas after reaching equilibrium. What was the equilibrium concentration of all three substances in this reaction? Include relevant chemical equations. (4 marks) 

 

(L3.2: Perform calculations to find the value of Keq and concentrations of substances within an equilibrium system and use these values to make predictions on the direction in which a reaction may proceed) 

Question 13

Explain how an increase in temperature can affect the Keq of an endothermic and exothermic reaction. (4 marks)

(L3.3: Qualitatively analyse the effect of temperature on the value of Keq)

Question 14

During the practical that investigates the Keq of iron (III) thiocyanate equilibrium, students obtained a different Keq value to that of the theoretical value. Suggest a source of error for this. (3 marks)

 

(L3.4: Conduct an investigation to determine Keq of a chemical equilibrium system, for example: Keq of the iron (III) thiocyanate equilibrium) 

Question 15

Deduce what would be observed in the following conditions. (6 marks)

 

(L3.5: Explore the use of Keq for different types of chemical reactions, including but not limited to: Dissociation of ionic solutions, Dissociation of acids and bases)

Solution Equilibria 

Question 16

Explain how the dissolution of cations differ to the dissolution of anions in water. Use diagrams if appropriate. (4 marks) 

 

(L4.1: Describe and analyse the processes involved in the dissolution of ionic compounds in water)

Question 17

How do Aboriginal and Torres Strait Islander People utilise the solubility equilibria to remove toxins in cycad fruits? (4 marks) 

 

(L4.2: Investigate the use of solubility equilibria by Aboriginal and Torres Strait Islander Peoples when removing toxicity from foods, for example: Toxins in cycad fruit)

Question 18

Complete the following table. (9 marks)

 

(L4.3: Conduct an investigation to determine solubility rules, and predict and analyse the composition of substances when two ionic solutions are mixed, for example: Potassium chloride and silver nitrate, Potassium iodide and lead nitrate, Sodium sulfate and barium nitrate)

Question 19

Calculate the the following (6 marks): 

a) What is the solubility of Sr2-when the Ksp of strontium sulfate is 3.44×10-7

b) What is the solubility of CO32-when the Ksp of calcium carbonate is 3.36×10-9

c) What is the solubility of CrO42- when the Ksp  of barium chromate is 1.2×10-10

 

(L4.4: Derive equilibrium expressions for saturated solutions in terms of Ksp and calculate the solubility of an ionic substance from its Ksp value) 

Question 20

25.0 mL of 0.0020 M potassium chromate are mixed with 75.0 mL of 0.000125 M lead(II) nitrate. Will a precipitate of lead(II) chromate form. Ksp of lead(II) chromate is 1.8 x 10-14 (3 marks)

 

(L4.5: Predict the formation of a precipitate when given the standard reference values for Ksp) 

And that wraps up our practice questions for HSC Chemistry Module 5: Equilibrium and Acid Reactions – good luck!

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Kate Lynn Law graduated in 2017 with an all rounders HSC award and an ATAR of 97.65. Passionate about mentoring, she enjoys working with high school students to improve their academic, work and life skills in preparation for the HSC and what comes next. An avid blogger, Kate had administrated a creative writing page for over 2000 people since 2013, writing to an international audience since her early teenage years.