46 Word equations 14-16 Working in groupsSelf assessmentPeer assessmentSharing objectives and criteriaQuestioningUsing feedbackUsing tests

In this activity, students work individually, reading and interpreting text by looking for patterns. It provides an opportunity for students to:

  • use word and symbol equations to describe reactions
  • use patterns in reactions to make predictions about other reactions
  • represent chemical reactions by word equations.

The materials can be used for diagnosis (to identify students needing practice), as a remedial exercise or for summative assessment.

Learning objectives

Students will:

  • understand that chemical reactions may be described by word equations
  • recognise that each type of chemical reaction has its own general word equation
  • be able to use word equations to describe chemical reactions.

Sequence of activities

Remind students of the term ‘word equation’.

Ask them to:

  • write an explanation of ‘word equation’ on a mini whiteboard
  • reveal their answers simultaneously.

Go around the displayed answers and make a brief comment on each.

Explain that the purpose of the lesson is to check their ability to write word equations.

Give each student the sheets Word equations 1 and Information to try.

Tell students not to write reasons for their answers, but to think about the reasons.

Select students to give their reasons at the end of the session.

Ask them to say what answers they are unsure about. Explain that there are a number of sheets that might help them with the parts they are finding difficult.

Suggest that they read the Information page. If this is insufficient, tell them to chose one or more of the following sheets and go through the exercises:

  • Word equation ‑ the reaction between acids and alkalis
  • Word equation ‑ the reaction between acids and metals
  • Word equation ‑ the reaction between acids and metal carbonates
  • Word equation ‑ displacement reactions
  • Word equation ‑ synthesis reactions.

When they feel able, ask each student to write answers to the questions they had been unsure about in Word equations 1.

Go through the correct answers to Word equations 1 with the class. Select students to give reasons for the answers.

Finally, give out copies of Completing and writing word equations. Ask students to answer the questions and include their reasons.

Require students to hand in this final sheet for checking. Comment as necessary.

Assessment for learning commentary

Students look at their own performance and identify their own weaknesses in a clear-cut way. They work through support material to suit their needs and then reassess their understanding. As students can see the standard they are aiming for and select their own means to achieve it, they are more likely to work with a positive attitude.

The final worksheet enables the teacher to be satisfied that students have reached an appropriate level and to give further support.

Where the materials are used as a remedial exercise or for summative assessment, teachers can have model answers available for students to check their own work.

Resources

For each student

  • Mini whiteboard
Download Word Download PDF Word equations 1 and Information
Download Word Download PDF Word equation ‑ the reaction between acids and alkalis
Download Word Download PDF Word equation ‑ the reaction between acids and metals
Download Word Download PDF Word equation ‑ the reaction between acids and metal carbonates
Download Word Download PDF Word equation ‑ displacement reactions
Download Word Download PDF Word equation ‑ synthesis reactions
Download Word Download PDF Completing and writing word equations

Answers

Word equations 1

  1. potassium nitrate
  2. nitric acid
  3. sulfuric acid
  4. calcium chloride
  5. magnesium chloride

The reaction between acids and alkalis

  1. Potassium chloride
    Sodium nitrate
  2. nitric acid + potassium hydroxide potassium nitrate + water
    sulfuric acid + sodium hydroxide sodium sulfate + water

The reaction between acids and metals

  1. iron nitrate
    zinc sulfate
    magnesium chloride; magnesium nitrate
  2. hydrochloric acid + calcium calcium chloride + hydrogen
    nitric acid + magnesium magnesium nitrate + water

The reaction between acids and metal carbonates

  1. copper chloride; copper sulfate
    zinc chloride; zinc nitrate
    iron nitrate; iron sulfate
  2. hydrochloric acid + magnesium carbonate magnesium chloride + water + carbon dioxide
    nitric acid + iron carbonate iron chloride + water + carbon dioxide

Displacement reactions

  1. magnesium + iron nitrate magnesium nitrate + iron
  2. magnesium + zinc sulfate magnesium sulfate + zinc
  3. magnesium + copper sulfate magnesium sulfate + copper
  4. zinc + copper sulfate zinc sulfate + copper
  5. zinc + iron chloride zinc chloride + iron
  6. zinc + iron sulfate zinc sulfate + iron
  7. zinc + copper sulfate zinc nitrate + copper
  8. iron + copper sulfate iron sulfate + copper
  9. iron + copper nitrate iron nitrate + copper

Synthesis reactions

  1. When sulfur reacts with a metal, the compound is called a sulfide.
    When fluorine reacts with a metal, the compound is called a fluoride.
  2. magnesium sulfide; magnesium chloride
    iron fluoride; iron chloride
    zinc oxide; zinc sulfide; zinc fluoride
    copper oxide; copper sulfide; copper chloride
  3. sodium + iodine sodium iodide
    nickel + sulfur nickel sulfide
    calcium + bromine calcium bromide

Completing and writing word equations

  1. sulfuric acid + sodium hydroxide sodium sulfate + water
  2. iron + iron chloride iron chloride + copper
  3. hydrochloric acid + magnesium carbonate magnesium chloride + water + carbon dioxide
  4. zinc + oxygen zinc oxide
  5. calcium + nitric acid calcium nitrate + hydrogen
  6. acid and alkali
    copper oxide + sulfuric acid copper sulfate + water
  7. acid and metal
    zinc + hydrochloric acid zinc chloride + hydrogen
  8. synthesis
    magnesium + chlorine magnesium chloride
  9. displacement
    copper + silver nitrate copper nitrate + silver
  10. acid and metal carbonate
    copper carbonate + sulfuric acid copper sulfate + carbon dioxide + water

Acknowledgement

K. Taber, Chemical Misconceptions. London: Royal Society of Chemistry, 2002.