Option D - Pharmaceuticals
Question 1
HLPaper 3Technetium-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.
a(i).
Technetium-99 decays further, emitting beta radiation. Formulate the equation for the decay of technetium-99.
a(ii).
Outline what is meant by low-level waste.
b(i).
Outline the disposal of LLW.
b(ii).
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.
Question 2
SLPaper 3Most of the nuclear waste generated in a hospital is low-level waste (LLW).
Outline what is meant by low-level waste.
Outline the disposal of LLW.
Question 3
SLPaper 3The buffer formed by carbon dioxide, CO2(aq) and hydrogen carbonate ion, HCO3−(aq),plays an important role in maintaining the pH of blood.
Calculate the pH of the buffer from the following data and section 1 of the data booklet.
p_K_a(CO2) = 6.34
[HCO3−(aq)] = 1.40 × 10−2 mol dm−3
[CO2(aq)] = 1.25 × 10−3 mol dm−3
Explain the effect of a large amount of aspirin on the pH of blood.
Question 4
HLPaper 3Excess stomach acid leads to medical conditions that affect many people worldwide. These conditions can be treated with several types of medical drugs.
Question 5
HLPaper 3Nuclear radiation is dangerous because of its ability to damage cells but it can also be usedin nuclear medicine.
Iodine-131 is released in nuclear explosions but is used in scanners for thyroid cancer.The half-life of iodine-131 is 8.02 days.
Yttrium-90 is used in treating certain cancers.
Formulate a nuclear equation for the beta decay of yttrium-90.
Lutetium-177 is a common isotope used for internal radiation therapy.
Suggest why lutetium-177 is an ideal isotope for the treatment of certain cancers basedon the type of radiation emitted.
Calculate the rate constant, λ, in day−1, for the decay of iodine-131 using section1 of the data booklet.
Calculate the time, in days, for 90% of the sample to decay.
A breathalyser measures the blood alcohol content from a breath sample.Formulate half-equations for the reactions at the anode (negative electrode) and thecathode (positive electrode) in a fuel cell breathalyser.
Question 6
SLPaper 3Mild heartburn is treated with antacids such as calcium carbonate.
Formulate an equation for the neutralization of stomach acid with calcium carbonate, CaCO3 (s).
a(i).
Determine the volume of CO2 (g), in dm3, produced at STP, when 1.00 g of CaCO3 (s) reacts completely with stomach acid.
Mr CaCO3 = 100.09
a(ii).
Acid secretion can be regulated by other types of drugs such as omeprazole and ranitidine. Outline how each of these drugs acts to reduce excess stomach acid.
Omeprazole:
Ranitidine:
Question 7
SLPaper 3Methadone, a synthetic opioid, binds to opioid receptors in the brain.
Compare and contrast the functional groups present in methadone and diamorphine (heroin), giving their names. Use section 37 of the data booklet.
Methadone is sometimes used to help reduce withdrawal symptoms in the treatment of heroin addiction. Outline one withdrawal symptom that an addict may experience.
Question 8
HLPaper 3Technetium-99m is the most widely used medical radioisotope. It is usually made on-site in medical facilities from isotopes of molybdenum.
Deduce equations for the following nuclear reactions:
(i) Molybdenum-98 absorbs a neutron.
(ii) The isotope produced in (a) (i) decays into technetium-99m.
Molybdenum-99 has a half-life of 66 hours, while technetium-99m has a half-life of 6 hours. Outline why technetium-99m is made on-site.
Outline two reasons, other than its half-life, why technetium-99m is so useful in medical diagnosis.
Outline the nature of the radioactive waste that is generated by the use of technetium-99m in medical diagnosis.
Question 9
SLPaper 3The structures of oseltamivir (Tamiflu) and zanamivir (Relenza) are given in section 37 of thedata booklet.
Compare and contrast the structures of oseltamivir and zanamivir, stating thenames of functional groups.
Deduce the wavenumber of one absorbance seen in the IR spectrum of only oneof the compounds, using section 26 of the data booklet.
Suggest one ethical consideration faced by medical researchers whendeveloping medications.
Question 10
HLPaper 3The structure of penicillin is shown in section 37 of the data booklet.
State the internal bond angles in the b-lactam ring and the expected bond angles in sp2and sp3 hybridised atoms.
Explain how the open β-lactam ring kills bacteria.
State how the structure of penicillin can be modified to combat the effect of resistancecaused by over prescription.
Suggest why human cells are not affected by penicillin.
