Topic 10 Practice Paper: Chemistry of the environment — question paper

Section A: Multiple-choice questions[10 marks]

Choose one answer for each question. Each question is worth 1 mark.

1. 1

   After nitrogen and oxygen, the remaining fraction of clean, dry air consists mainly of

   1. Acarbon dioxide only
   2. Bhydrogen and helium
   3. Cmethane
   4. Dnoble gases with a little carbon dioxide
   ( )
2. 2

   Which impurity in coal produces sulfur dioxide when the coal burns?

   1. ACarbon
   2. BSulfur compounds
   3. CNitrogen compounds
   4. DClay minerals
   ( )
3. 3

   Which gas makes up about 21% of clean, dry air?

   1. AOxygen
   2. BNitrogen
   3. CArgon
   4. DCarbon dioxide
   ( )
4. 4

   River water contains a dissolved substance that is essential for fish and other aquatic organisms. The substance is

   1. Aplastics
   2. Bnitrates
   3. Cdissolved oxygen
   4. Dsewage
   ( )
5. 5

   A gardener wants one product that supplies nitrogen, phosphorus and potassium together. The gardener should buy

   1. Aammonium nitrate
   2. Bcalcium carbonate
   3. Cammonium sulfate
   4. Dan NPK fertiliser
   ( )
6. 6

   Anhydrous cobalt(II) chloride paper is used in the laboratory to test for

   1. Athe presence of water
   2. Bthe purity of water
   3. Cdissolved salts
   4. Dwater hardness
   ( )
7. 7

   A colourless liquid cools and begins to solidify gradually over several degrees. The liquid is

   1. Aa pure element
   2. Ba mixture containing dissolved impurities
   3. Cundergoing chemical decomposition
   4. Dboiling
   ( )
8. 8

   Which combination of processes removes insoluble solids during domestic water treatment?

   1. AChlorination followed by carbon treatment
   2. BFiltration followed by distillation
   3. CSedimentation followed by filtration
   4. DSedimentation followed by chlorination
   ( )
9. 9

   Farmers spread ammonium nitrate on fields mainly because it supplies plants with

   1. Aphosphorus
   2. Bnitrogen
   3. Cpotassium
   4. Doxygen
   ( )
10. 10

    Methane enters the atmosphere in significant quantities from

    1. Acar engines
    2. Bburning coal
    3. Cvolcanic eruptions
    4. Ddecomposing vegetation and animal digestion
    ( )

Section B: Structured questions[20 marks]

Answer all questions in the spaces provided.

1. 11

   A school laboratory uses distilled water for making solutions, while the taps supply mains water.

   1. (a)

      Explain why distilled water, not tap water, is used for practical chemistry.

      [2]
   2. (b)

      A sample of laboratory water boils at 100.6 °C at standard pressure. Comment on its purity.

      [1]
   3. (c)

      The water company supplying the taps reports a muddy, unpleasant-tasting supply. Name the two treatment stages that would remove the mud.

      [1]
   4. (d)

      Name the treatment stage that would remove the unpleasant taste.

      [1]
2. 12

   A farmer manages a field used for growing wheat and keeps a herd of dairy cattle.

   1. (a)

      Name the three elements that an NPK fertiliser supplies.

      [1]
   2. (b)

      Explain why the farmer needs to add fertilisers to the field regularly.

      [2]
   3. (c)

      Name the ammonium salt, made from ammonia solution and nitric acid, that is a common nitrogen fertiliser.

      [1]
   4. (d)

      Heavy rain washes excess fertiliser into a nearby river. State one harmful consequence for the river ecosystem.

      [1]
3. 13

   A country plans to cut its greenhouse-gas emissions. Its main sources are a coal-fired power station, large cattle farms and heavy road traffic.

   1. (a)

      Name the two gases emitted by these sources that raise the average temperature of the Earth.

      [1]
   2. (b)

      Describe what these gas molecules do to thermal energy leaving the Earth’s surface.

      [2]
   3. (c)

      Suggest two changes for this country that would reduce its emissions, one for the cattle farms and one for the roads.

      [2]
4. 14

   Traffic engineers are testing exhaust gases from a busy city road for pollutants and their controls.

   1. (a)

      Name the two gases from the air that react in a hot engine to form an oxide of nitrogen, and state the condition inside the engine that makes them react.

      [2]
   2. (b)

      Inside a catalytic converter, nitrogen oxide reacts with carbon monoxide. Write the equation for this reaction.

      [1]
   3. (c)

      State two adverse effects of oxides of nitrogen.

      [1]
   4. (d)

      Name one pollutant released by the same traffic when fuel burns with too little air, and state one of its effects.

      [1]