| Date | May 2019 | Marks available | 2 | Reference code | 19M.3.hl.TZ1.6 |
| Level | HL | Paper | 3 | Time zone | TZ1 |
| Command term | Describe | Question number | 6 | Adapted from | N/A |
Question
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.
Markscheme
Structure:
giant covalent/network covalent [✔]
Bonding:
each carbon covalently bonded to 3 other carbons
OR
each bond has order of 1.5 [✔]
Note: Accept “cylindrical/tube shaped”.
Accept “has delocalized electrons” OR “has sp2 hybridization”.
Any one of:
3D electrodes [✔]
catalysts [✔]
biosensors [✔]
molecular stents [✔]
body armour [✔]
synthetic muscles [✔]
micro transistors/circuitry/capacitors/electrodes [✔]
reinforcing phase in a matrix/composite material «such as concrete» [✔]
micro antenna [✔]
stealth technology [✔]
water/air filtration [✔]
solar cells [✔]
tennis racquets [✔]
microelectronic circuits [✔]
Note: Do not accept just general answers such as “medicine” or “defence”.
Examiners report
Describing the structure and bonding of a carbon nanotube was generally answered satisfactorily, although some candidates simply said the bonding was covalent with no further detail.
There were some vague responses for applications of carbon nanotubes when specific details were needed to score the mark in (b).
Syllabus sections
-
17N.3.sl.TZ0.6a:
State equations for the formation of iron nanoparticles and carbon atoms from Fe(CO)5 in the HIPCO process.
- 17N.3.sl.TZ0.6c: Discuss one possible risk associated with the use of nanotechnology.
-
19M.3.hl.TZ2.4e:
Carbon nanotubes are added to metals to increase tensile strength.
Write an equation for the formation of carbon nanotubes from carbon monoxide.
-
18N.3.sl.TZ0.4c:
Arc discharge, consisting of two inert metal electrodes in a liquid solvent, is one method of producing carbon nanotubes (CNTs).
Predict, giving a reason, the electrode at which the solvent cyclohexane, C6H12, will decompose to form CNTs.
-
19M.3.sl.TZ1.6a:
Describe the structure and bonding of a carbon nanotube.
Structure:
Bonding:
-
19M.3.sl.TZ2.4e:
Carbon nanotubes are added to metals to increase tensile strength.
Write an equation for the formation of carbon nanotubes from carbon monoxide.
-
19M.3.hl.TZ1.6b:
Suggest one application for carbon nanotubes.
-
17M.3.sl.TZ1.8b:
Suggest why nanoparticles need to be handled with care.
-
17M.3.sl.TZ1.8a:
State the major advantage that nanoparticles have in these applications.
- 17N.3.sl.TZ0.6b: Outline why the iron nanoparticle catalysts produced by the HIPCO process are more efficient...
-
19N.3.sl.TZ0.3c:
Nanotubes are used to support the active material in nanocatalysts.
Explain why oxygen cannot be used for the chemical vapour deposition (CVD) preparation of carbon nanotubes.
-
18M.3.sl.TZ2.5a:
State the source of carbon for MWCNT produced by arc discharge and by CVD.
-
18M.3.sl.TZ1.3b.iii:
Describe how carbon nanotubes are produced by chemical vapour deposition (CVD).
-
16N.3.sl.TZ0.5b:
Nanocatalysts play an essential role in the manufacture of industrial chemicals.
(i) Describe the high pressure carbon monoxide (HIPCO) method for the production of carbon nanotubes.
(ii) Outline one benefit of using nanocatalysts compared to traditional catalysts in industry.
-
19M.3.sl.TZ1.6b:
Suggest one application for carbon nanotubes.
-
18M.3.sl.TZ1.3b.ii:
State one physical property of HDPE that will be affected by the incorporation of carbon nanotubes.
- 20N.3.sl.TZ0.4a: Explain these properties of carbon nanotubes.
- 20N.3.hl.TZ0.4a: Explain these properties of carbon nanotubes.
