| Date | May 2018 | Marks available | 2 | Reference code | 18M.3.sl.TZ2.8 |
| Level | SL | Paper | 3 | Time zone | TZ2 |
| Command term | Outline | Question number | 8 | Adapted from | N/A |
Question
Green Chemistry reduces the production of hazardous materials and chemical waste.
Outline two specific examples or technological processes of how Green Chemistry has accomplished this environmental impact.
Markscheme
Any two of:
replaces plastics with biodegradable/starch/cellulose based plastics
use enzymes instead of polluting detergents/phosphates
OR
use of enzymes means lower temperatures can be used
OR
use enzymes instead of emulsifiers to treat oil spills
OR
use enzymes to produce esters at lower temperatures/without sulfuric acid
replace organic/toxic solvents with carbon dioxide
replace polymers from fossil fuel with bamboo/renewable resources
develop paint resins reducing production of volatile compounds «when paint is applied»
industrial synthesis of ethanoic/acetic acid from methanol and carbon monoxide has 100% atom economy
energy recovery
Accept formulas for names.
Award mark for any other reasonable specific green chemistry example that prevents the release of pollutants/toxic chemicals into the environment by changing the method or the materials used.
Do not award mark for methods that involve clean-up of pollutants from the environment such as host-guest chemistry or alternative energy sources.
[2 marks]
Examiners report
Syllabus sections
-
17M.3.sl.TZ1.13f:
Outline how lead ions could be removed from an individual suffering from lead poisoning.
- 19N.3.hl.TZ0.14b: Explain the biomagnification of the pesticide DDT.
- 18N.3.sl.TZ0.5c: Explain how a xenobiotic is biomagnified.
- 18N.3.sl.TZ0.6b.ii: Enzymes are widely used in washing detergents. Outline how they improve the efficiency of the...
- 19N.3.sl.TZ0.10b: Explain the biomagnification of the pesticide DDT.
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19M.3.sl.TZ2.6c(ii):
Oil spills can be treated with an enzyme mixture to speed up decomposition.
Outline one factor to be considered when assessing the greenness of an enzyme mixture.
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16N.3.sl.TZ0.9c:
Amylose is an unbranched polysaccharide composed of repeating units of glucose.
(i) Draw the structure of the repeating unit of amylose. Use section 34 of the data booklet.
(ii) Amylose is a major component of starch. Corn starch can be used to make replacements for plastics derived from oil, especially for packaging. Discuss one potential advantage and one disadvantage of this use of starch.
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18M.3.sl.TZ1.7c.iii:
Explain why sharks and swordfish sometimes contain high concentrations of mercury and polychlorinated biphenyls (PCBs).
- 19N.3.sl.TZ0.8c: State one use of enzymes in reducing environmental problems.
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19M.3.hl.TZ1.8d:
Explain how the inclusion of starch in plastics makes them biodegradable.
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19M.3.sl.TZ2.6c(i):
Suggest two reasons why oil decomposes faster at the surface of the ocean than at greater depth.
-
17M.3.sl.TZ1.12c.i:
State one advantage of starch based polymers besides being biodegradable.
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19M.3.hl.TZ2.9d(ii):
Oil spills can be treated with an enzyme mixture to speed up decomposition.
Outline one factor to be considered when assessing the greenness of an enzyme mixture.
-
17M.3.sl.TZ2.10d:
Suggest one of the challenges scientists face when scaling up the synthesis of a new compound.
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17M.3.sl.TZ2.10c:
Starch is a constituent of many plastics. Suggest one reason for including starch in plastics.
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17N.3.sl.TZ0.9c:
Explain how the inclusion of carbohydrates in plastics makes them biodegradable.
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17M.3.sl.TZ1.13e:
Pollution from heavy metal ions has become a health concern.
Outline how the presence of heavy metal ions decreases the action of enzymes.
-
19M.3.hl.TZ2.9d(i):
Suggest two reasons why oil decomposes faster at the surface of the ocean than at greater depth.
-
18M.3.sl.TZ1.7c.iv:
Plastics are another source of marine pollution. Outline one way in which plastics can be made more biodegradable.
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19M.3.sl.TZ1.7d:
Explain how the inclusion of starch in plastics makes them biodegradable.
- 20N.3.sl.TZ0.8b: Suggest, with a reason, if fat-soluble or water-soluble xenobiotics would have a larger BMF.
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20N.3.sl.TZ0.8a:
Calculate the BMF if a shark consumes mackerel in one year. Each mackerel weighs on average. The per body weight. Assume chemical remains in the shark’s body for two years.
