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Boss quiz

10 questions on the whole topic. You get one try at each.

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  1. Which of these is a chemical change?

    • Frying an egg
    • Boiling water
    • Dissolving sugar in tea
    • Melting ice

  2. What are the substances at the start of a chemical reaction called?

    • Products
    • Reactants
    • Mixtures
    • Catalysts

  3. What happens to the atoms in a chemical reaction?

    • New atoms are made
    • They turn into other kinds of atom
    • They are destroyed
    • They are rearranged

  4. Magnesium burns in oxygen. Which word equation is right?

    • magnesium → oxygen + magnesium oxide
    • magnesium oxide → magnesium + oxygen
    • magnesium + oxygen → magnesium oxide
    • magnesium + magnesium oxide → oxygen

  5. 8 g of reactants are sealed in a flask and react completely. What is the total mass of the products?

    • 8 g
    • Less than 8 g
    • More than 8 g
    • 0 g

  6. Methane burns in plenty of oxygen. What are the products?

    • Carbon dioxide and water
    • Carbon and hydrogen
    • Oxygen and water
    • Methane oxide

  7. Which three things does a fire need?

    • Fuel, water and heat
    • Oxygen, nitrogen and heat
    • Fuel, oxygen and heat
    • Fuel, carbon dioxide and light

  8. Green copper carbonate is heated strongly. What is made?

    • Copper carbonate gas
    • Copper oxide and oxygen
    • Copper oxide and carbon dioxide
    • Copper and carbon

  9. A reaction makes its surroundings colder. What kind of reaction is it?

    • Neutralisation
    • Endothermic
    • Combustion
    • Exothermic

  10. What does a catalyst do?

    • Stops a reaction from starting
    • Gets used up to make more product
    • Slows a reaction down
    • Speeds up a reaction without being used up
Answers
  1. Frying an egg. Frying makes new substances and cannot be undone. The other three make no new substance.
  2. Reactants. Reactants react together. The new substances they make are the products.
  3. They are rearranged. The same atoms are there at the end, joined in a new way.
  4. magnesium + oxygen → magnesium oxide. The reactants, magnesium and oxygen, go before the arrow. The product goes after it.
  5. 8 g. Mass is conserved. No atoms can get in or out of a sealed flask.
  6. Carbon dioxide and water. The carbon in the fuel ends up in carbon dioxide and the hydrogen ends up in water.
  7. Fuel, oxygen and heat. These are the three sides of the fire triangle. Take one away and the fire goes out.
  8. Copper oxide and carbon dioxide. Heat breaks it down into black copper oxide and carbon dioxide gas. This is thermal decomposition.
  9. Endothermic. An endothermic reaction takes energy in from the surroundings, so the temperature goes down.
  10. Speeds up a reaction without being used up. A catalyst makes a reaction faster and is still there, unchanged, at the end.