Chemistry 9701 · AS & A Level · States of matter

States of matter — practice question

Before 1985, carbon was believed to occur in only two structural forms, or allotropes. In 1985, a new form, buckminsterfullerene, was discovered; in this allotrope, the carbon atoms are arranged as spherical molecules.
(a)

The other two forms of carbon have very different structures.

(a(i))

Name the two forms shown.

(a(ii))[4]

Give three differences in physical properties for these two forms.

(b)[2]

The diagram shows the structure of buckminsterfullerene. A buckminsterfullerene molecule contains 60 carbon atoms. Suggest why buckminsterfullerene reacts with hydrogen under suitable conditions, and give the formula of the product.

(c(i))

Graphene is made of sheets of carbon one atom thick. Calculate the number of carbon atoms in a sheet of graphene with a mass of $0.001\,\text{g}$.

(c(ii))

You may assume that the number of hexagons in a large sheet of graphene is one half of the number of carbon atoms. Each hexagon has an area of $690\,\text{nm}^2$. Calculate the area of the graphene sheet in (i).

(c(iii))[4]

Would you expect samples of graphene and buckminsterfullerene to conduct electricity? Explain your answers.

Worked solution & mark scheme

This 10-mark question has a full step-by-step worked solution and mark scheme.

  • Full mark scheme, point by point
  • Step-by-step worked solution
  • Write your answer & get it marked instantly by AI