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Question 18M.3.sl.TZ2.c

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Date May 2018 Marks available [Maximum mark: 2] Reference code 18M.3.sl.TZ2.c
Level sl Paper 3 Time zone TZ2
Command term Suggest Question number c Adapted from N/A
c.
[Maximum mark: 2]
18M.3.sl.TZ2.c

The table summarizes some properties of graphite and graphene.

M18/4/CHEMI/SP3/ENG/TZ2/01

The melting point of diamond at 1 × 106 kPa is 4200 K (in the absence of oxygen).

Suggest, based on molecular structure, why graphene has a higher melting point under these conditions.

[2]

Markscheme

shorter bonds in graphene

OR

bonds in graphene intermediate between single and double

OR

bond order in graphene is 1.33

OR

delocalization creates stronger bonds

OR

shorter bonds are stronger

 

stronger/shorter bonds require higher temperature/faster thermal motion to be altered

OR

stronger/shorter bonds require greater energy to be broken

 

[2 marks]

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