CIE Nov 2013 v3 Paper 4 Q9

Answers available below

Examiners For Use Until 1985, carbon was thought to exist in only two structural forms or allotropes. In 1985 another form, buckminsterfullerene, was discovered, in which the carbon exists as spherical molecules. 18 (a) The other two forms of carbon have very different structures. (i) Name these two forms.and(ii) Give three differences in physical properties between these two forms.[4] (b) The diagram shows the structure of buckminsterfullerene. buckminsterfullerene The molecule of buckminsterfullerene contains 60 carbon atoms. Suggest a reason why buckminsterfullerene reacts with hydrogen under suitable conditions and give a formula for the product.[2]UCLES 2013 9701/43/O/N/13<br /> Examiners For Use 19 (c) In 2010, two scientists from the University of Manchester were awarded the Nobel Prize for Physics for their work on graphene, a new structural form of carbon. Graphene is one of the new nano-materials being developed for commercial uses in the next 10 years. graphene (i) Graphene is in the form of sheets of carbon one atom thick. Calculate the number of carbon atoms present in a sheet of graphene with a mass of one thousandth of a gram (0.001 g). The number of hexagons in a large sheet of graphene can be assumed to be one half of the number of carbon atoms. Each hexagon has an area of 690 nm2. (ii) Calculate the area of the sheet of graphene in (i). area of sheet =nm2 (iii) Would you expect samples of graphene and buckminsterfullerene to be electrical conductors? Explain your answers. graphenebuckminsterfullereneUCLES 2013 9701/43/O/N/13 [4] [Total: 10] [Turn over<br />

Show answer