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Could You Pass A-Level Chemistry Now?

Warning: This is pretty tough. Based on real AQA past exam papers.

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  1. 1. Which of these atoms has the largest atomic radius?

    Correct
    Incorrect
    Via ptable.com
    Correct
    Incorrect
    Correct
    Incorrect
    Correct!
    Wrong!

    Atomic radius decreases from left to right across the periodic table.

    Via ptable.com
  2. 2. What is the definition of a structural isomer?

    en.wikipedia.org
    Correct
    Incorrect
    "A compound with the same molecular formula but a different structural formula."
    Correct
    Incorrect
    "A compound with a different molecular formula but the same structural formula."
    Correct!
    Wrong!

    In structural isomers atoms are arranged in completely different orders. You can't just twist two structural isomers in space to make them look the same again.

  3. 3. What reaction conditions are needed for thermal cracking to take place?

    emojipedia.org / BuzzFeed
    Correct
    Incorrect
    High temperature
    Correct
    Incorrect
    High pressure
    Correct
    Incorrect
    Both high temperature and high pressure
    Correct!
    Wrong!

    Thermal cracking requires temperatures in the hundreds of degrees, and tens of atmospheres of pressure.

  4. 4. Complete the sentence:

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    Correct
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    Correct!
    Wrong!

    This is in contrast to catalytic cracking, which produces It also produces high proportions of branched alkanes.

  5. 5. Which of these atoms has the smallest number of neutrons?

    Correct
    Incorrect
    Correct
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    Correct
    Incorrect
    Correct
    Incorrect
    Correct!
    Wrong!

    Hydrogen has one proton, helium has two, and lithium has three. You're given the mass numbers in the question, so you can work out how many neutrons each has from this information. 3H has two neutrons, 4He and 5He have two and three respectively, and 4Li has one neutron.

  6. 6. Which of these statements about ethene is correct?

    en.wikipedia.org
    Correct
    Incorrect
    It has no geometric isomers because there is free rotation around the C=C bond.
    Correct
    Incorrect
    It burns in excess oxygen to produce carbon dioxide and water.
    Correct
    Incorrect
    The C=C bond is twice as strong as the C–C bond in ethane.
    Correct!
    Wrong!

    When there's plenty of oxygen, all hydrocarbons burn to produce carbon dioxide and water.

  7. 7. Complete this sentence:

    Correct
    Incorrect
    Correct
    Incorrect
    Correct!
    Wrong!

    Reduction happens when a substance gains electrons during a chemical reaction, and oxidation is when a substance loses electrons.

  8. 8. Which of these is the best reducing agent?

    Correct
    Incorrect
    Correct
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    Correct
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    Correct
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    Correct!
    Wrong!

    A reducing agent is what gives electrons in a redox reaction. Strong reducing agents easily lose electrons.

  9. 9. Which statement about ethanal is correct?

    UAWiki / en.wikipedia.org
    Correct
    Incorrect
    It reacts with Tollens’ reagent to form silver.
    Correct
    Incorrect
    It has a higher boiling point than ethanol.
    Correct
    Incorrect
    Its empirical and molecular formulas are different.
    Correct!
    Wrong!

    Tollen's reagent determines the presence of an aldehyde.

  10. 10. Which of these substances does not contribute to the greenhouse effect?

    Correct
    Incorrect
    Unburned hydrocarbons
    Correct
    Incorrect
    Water vapour
    Correct
    Incorrect
    Carbon dioxide
    Correct
    Incorrect
    Nitrogen
    Correct!
    Wrong!

    On its own, molecular nitrogen (N2) does not retain heat so is not a greenhouse gas.

  11. 11. Which of these is the full electron configuration of a cobalt(II) ion?

    Correct
    Incorrect
    1s2 2s2 2p6 3s2 3p6 3d7
    Correct
    Incorrect
    1s2 2s2 2p6 3s2 3p6 3d7 4s2
    Correct!
    Wrong!

    Cobalt atoms lose their two electrons from the 4s orbital when they become a cobalt(II) ion.

  12. 12. Which compound gives a colourless solution when an excess of dilute aqueous ammonia is added?

    Correct
    Incorrect
    Correct
    Incorrect
    Correct
    Incorrect
    Correct
    Incorrect
    Correct!
    Wrong!

    AgCl dissolves to give a colourless solution when aqueous ammonia is added.

Kelly Oakes is science editor for BuzzFeed and is based in London.

Contact Kelly Oakes at kelly.oakes@buzzfeed.com.

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