HL Paper 3
Nanotechnology has allowed the manipulation of materials on the atomic level.
Describe the structure and bonding of a carbon nanotube.
Structure:
Bonding:
Suggest one application for carbon nanotubes.
Technetium-99m, a widely used radionuclide, has a half-life of 6.0 hours and undergoes gamma decay to technetium-99.
Most of the nuclear waste generated in a hospital is low-level waste (LLW).
Determine the percentage of technetium-99m remaining after 24.0 hours.
Technetium-99 decays further, emitting beta radiation. Formulate the equation for the decay of technetium-99.
Outline what is meant by low-level waste.
Outline the disposal of LLW.
Magnetic resonance imaging (MRI) is an application of NMR technology using radiowaves.
Suggest why MRI is much less dangerous than imaging techniques such as X-rays and radiotracers. Use section 3 of the data booklet.
The discovery of penicillins contributed to the development of antibiotics.
Explain how the beta-lactam ring is responsible for the antibiotic properties of penicillin. Refer to section 37 of the data booklet.
Outline the impact of antibiotic waste on the environment.
Suggest a concern about the disposal of solvents from drug manufacturing.
Discuss two difficulties, apart from socio-economic factors, associated with finding a cure for AIDS.
Proteins have structural or enzyme functions.
Oil spills are a major environmental problem.
Some proteins form an α-helix. State the name of another secondary protein structure.
Compare and contrast the bonding responsible for the two secondary structures.
One similarity:
One difference:
Explain why an increase in temperature reduces the rate of an enzyme-catalyzed reaction.
State and explain how a competitive inhibitor affects the maximum rate, Vmax, of an enzyme-catalyzed reaction.
Suggest two reasons why oil decomposes faster at the surface of the ocean than at greater depth.
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.
This question is about nuclear reactions.
Fission of a nucleus can be initiated by bombarding it with a neutron.
Determine the other product of the fission reaction of plutonium-239.
Outline the concept of critical mass with respect to fission reactions.
Outline one advantage of allowing all countries access to the technology to generate electricity by nuclear fission.
State one advantage of using fusion reactions rather than fission to generate electrical power.
Outline how the energy of a fission reaction can be calculated.
Calculate the half-life of an isotope whose mass falls from 5.0 × 10−5 g to 4.0 × 10−5 g in 31.4 s, using section 1 of the data booklet.
Consider the following data for butane and pentane at STP.
Discuss the data.
Outline what is meant by the degradation of energy.
New genetically modified organisms (GMO), especially plants, are continually being developed in research laboratories.
Outline what is meant by genetically modified organisms.
Outline one benefit of the use of these products.
DNA, deoxyribonucleic acid, is made up of nucleotides.
List two components of nucleotides.
Explain how the double-helical structure of DNA is stabilized once formed.
Natural gas is an energy source composed mainly of methane.
Natural gas is burned to produce steam which turns turbines in an electricity generating power plant.
The efficiency of several sources for power plants is given below.
Calculate the specific energy of methane, in MJ kg−1, using sections 1, 6 and 13 of the data booklet.
Calculate the maximum electric energy output, in MJ, which can be obtained from burning 1.00 kg of methane by using your answer from (a).
Hydroelectric power plants produced 16% of the world’s energy in 2015, down from 21% in 1971.
Suggest why hydroelectric power production has a higher efficiency than the other sources given in (b) and why its relative use has decreased despite the high efficiency.
Reason for higher efficiency:
Reason for decreased use:
Methane can also be obtained by fractional distillation of crude oil.
[Source: Image used with kind permission of science-resources.co.uk]
Draw a circle on the diagram to show where the methane fraction is withdrawn.
List the following products, which are also obtained by fractional distillation, according to decreasing volatility: asphalt, diesel, gasoline, lubricating motor oil.
Explain how methane absorbs infrared (IR) radiation by referring to its molecular geometry and dipole moment.
Compare methane’s atmospheric abundance and greenhouse effect to that of carbon dioxide.
Polymers have a wide variety of uses but their disposal can be problematic.
Draw a section of isotactic polychloroethene (polyvinylchloride, PVC) showing all the atoms and all the bonds of four monomer units.
The infrared (IR) spectrum of polyethene is given.
Suggest how the IR spectrum of polychloroethene would diff er, using section 26 of the data booklet.
Explain how plasticizers affect the properties of plastics.
Suggest why the addition of plasticizers is controversial.
Outline, giving a reason, how addition and condensation polymerization compare with regard to green chemistry.
Draw the full structural formula of the organic functional group formed during the polymerization of the two reactants below.
