Start learning →

NSC / Matric Chemical Equilibrium — practice questions

Explore 5 free Chemical Equilibrium questions in NSC / Matric Chemistry. Open each question or exercise to read its content, reference answers and available explanation.

Practise Chemical Equilibrium with Quill →

Chemical Equilibrium questions and exercises with answers

Showing questions 1–5 of 5.

When is a reversible reaction said to be at chemical equilibrium?Read the answer and worked solution →Which kind of system lets energy move in and out but keeps all its matter inside?Read the answer and worked solution →A mixture at equilibrium is heated. Which of the two reactions is then favoured?Read the answer and worked solution →Sort each clue: galvanic or electrolyticRead the answer and worked solution →Tap the word that breaks the ruleRead the answer and worked solution →

Worked practice questions

When is a reversible reaction said to be at chemical equilibrium?

  1. Forward and reverse rates are zero
  2. Forward and reverse rates are equal
  3. All the reactants have been used up
  4. The forward rate is much larger
Show answer and solution

Correct answer: B. Forward and reverse rates are equal

1. In a reversible reaction the products can turn back into the reactants. 2. As the reactants run down the forward reaction slows, and as products build up the reverse reaction speeds up. 3. Eventually the two rates become equal and the amounts of reactant and product stop changing. 4. That balance point is what is meant by chemical equilibrium. _Source: Siyavula Physical Sciences Grade 12 (Everything Science, CC BY 4.0), Chapter 8: Chemical equilibrium_

Open this question →

Which kind of system lets energy move in and out but keeps all its matter inside?

  1. An open system
  2. An empty system
  3. A closed system
  4. A perfect system
Show answer and solution

Correct answer: C. A closed system

1. A beaker of water left uncovered loses water vapour to the room, so matter escapes. 2. The same beaker with a glass cover still heats and cools, but the vapour condenses and falls back. 3. A system that exchanges only energy, never matter, is a closed system. 4. Reactions can reach equilibrium only in a closed system, because nothing is allowed to leave. _Source: Siyavula Physical Sciences Grade 12 (Everything Science, CC BY 4.0), Chapter 8: Chemical equilibrium_

Open this question →

A mixture at equilibrium is heated. Which of the two reactions is then favoured?

  1. The exothermic one
  2. The faster one only
  3. The slower one only
  4. The endothermic one
Show answer and solution

Correct answer: D. The endothermic one

1. Le Chatelier's principle says the equilibrium shifts so as to reduce the effect of any change forced on it. 2. Raising the temperature is a change the system will try to oppose by cooling itself. 3. The reaction that takes energy in is the endothermic one. 4. So heating a mixture at equilibrium favours the endothermic reaction. 5. Cooling the mixture would do the opposite and favour the exothermic reaction instead. _Source: Siyavula Physical Sciences Grade 12 (Everything Science, CC BY 4.0), Chapter 8: Chemical equilibrium_

Open this question →

How to practise

  1. Choose a Chemical Equilibrium question and try to work out your answer.
  2. Open the question to check the correct answer and read its worked solution.
  3. Continue in the app for bite-sized lessons, explanations and review with Quill. You can start without creating an account.

More Chemistry topics

Organic MoleculesElectrochemical ReactionsAcids and BasesRate and Extent of ReactionThe Chemical Industry