Chemical reactions

Understand the difference between physical and chemical changes and write equations using word and symbol equations.

Chemical reactions

Understand the difference between physical and chemical changes and write equations using word and symbol equations.

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Lesson details

Key learning points

  1. Distinguish between physical and chemical changes
  2. Write chemical equations to show the formation of compounds
  3. Write chemical equations to show displacement reactions
  4. Write chemical equations to show the decomposition of compounds

Equipment

Periodic table

Licence

This content is made available by Oak National Academy Limited and its partners and licensed under Oak’s terms & conditions (Collection 1), except where otherwise stated.

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6 Questions

Q1.
When chocolate changes from a solid to a liquid, it is called .
Correct Answer: melting, melt, liquifying, liquify
Q2.
What is the process called when water changes from a liquid to a gas?
Correct answer: boiling
condensing
freezing
melting
Q3.
Match the compounds to their descriptions.
Correct Answer:iron sulfide,A substance made from iron and sulfur.

A substance made from iron and sulfur.

Correct Answer:hydrogen chloride,A substance made from hydrogen and chlorine.

A substance made from hydrogen and chlorine.

Correct Answer:sodium carbonate,A substance made from sodium, carbon and oxygen.

A substance made from sodium, carbon and oxygen.

Correct Answer:iron sulfate,A substance made from iron, sulfur and oxygen.

A substance made from iron, sulfur and oxygen.

Q4.
If a compound contains three elements and one is oxygen, the name ends in …
-ade
Correct answer: -ate
-ide
-ite
Q5.
How can you tell when an egg is cooking in a frying pan?
Correct answer: It bubbles.
Correct answer: It changes colour.
It gets colder.
It produces a flash of light.
The smell disappears.
Q6.
Which of the following is a chemical reaction?
chopping an apple
Correct answer: exploding fireworks
melting chocolate
ripping up paper

6 Questions

Q1.
Which two are signs that a chemical reaction has taken place?
Correct answer: A colour change occurred.
Correct answer: A new product was formed.
The substance changed state.
The substance was broken into smaller pieces.
The substances were mixed together.
Q2.
A substance changes from a gas to a liquid. This is a change.
Correct Answer: physical
Q3.
Select the correct word equation for the following reaction: propane and oxygen react together to produce carbon dioxide and water.
carbon dioxide + water → propane + oxygen
carbon dioxide + water = propane + oxygen
Correct answer: propane + oxygen → carbon dioxide + water
propane + oxygen = carbon dioxide + water
Q4.
To balance a symbol equation…
Correct answer: the number of atoms of each element must be equal on both sides.
the number of atoms of each element must be higher in the products than the reactants.
the number of atoms of each element must be lower in the products than the reactants.
Q5.
Match the type of chemical reaction to the equation.
Correct Answer:decomposition,magnesium carbonate → magnesium oxide + carbon dioxide

magnesium carbonate → magnesium oxide + carbon dioxide

Correct Answer:displacement,copper oxide + zinc → zinc oxide + copper

copper oxide + zinc → zinc oxide + copper

Correct Answer:neither displacement nor decomposition,nickel + oxygen → nickel oxide

nickel + oxygen → nickel oxide

Q6.
What is the balanced symbol equation for copper + oxygen → copper oxide?
2 CO plus O2 reactants to become 2CoO
Co plus O reactants to become CoO
Cu plus O reactants to become CuO
Correct answer: 2 Cu plus O2 reactants to become 2 Cu O

Lesson appears in

UnitScience / Atoms and the periodic table

Science