CHE216

Assessed Coursework 1

Submit your answers as a separate file

Deadline Friday 21 March 16:00 h

1 The molecule ammonia, NH3, had C3v symmetry and the molecule boron trifluoride, BF3, had D3v symmetry.

Explain why the symmetry of NH3 begins with a “C” while that of BF3 begins with a “D.”   [5 marks]

2 Explain what is meant by the term symmetry element.    [5 marks]

3 Explain what is meant by the term symmetry operation.   [5 marks]

4 Explain what is meant by each of the following symmetry operations.

i) σv,

ii) σd,

iii) σh,

iv) i,

v) S3.

[2 marks each]

5 Draw diagrams showing every symmetry element in each of the molecules below.    [10 marks each]

6 Identify the symmetry group of each of the molecules below.             [5 marks each]