Chemistry

Assignment 04 A
1- Which of the following does not contain a C3 axis? a) b) c) d) POCl3 [NH4]+ [H3O]+ ClF3

2- Which of the following symmetry elements does cis-N2F2 contain? a) a C2 axis b) a h plane c) an inversion centre, i d) an S2 axis

3- Which if the following species possesses both C3 and C2 axes? a) b) c) d) SO3 NH3 PCl3 [H3O]+

4- Which two species belong to the same point group? a) b) c) d) XeF2 and OF2 H2O and CO2 H2S and OF2 [NO2]+ and [NO2]–

5- Which of the following belongs to the C3v point group? a) b) c) d) SO3 BBr3 NH3 AlCl3

6- Which molecule does not have Td symmetry? a) b) c) d) SiF4 P4 CH4 XeF4

7- Which molecule or ion has D3h symmetry? a) b) c) d) [H3O]+ CHCl3 [CO3]2– NF3

8- SO2 belongs to which point group? a) b) c) d) C2v C2 D∞h C2h

9- Which of the following molecules or ions possesses a C4 principal axis? a) b) c) d) XeF4 CF4 SF4 [PF4]+

10- Which of the following molecules or ions possesses an inversion centre (centre of symmetry)? a) b) c) d) [PF6]– SiH4 BF3 PF5

11- Which of the following molecules or ions belongs to the C4v point group? a) b) c) d) SF5Cl [BH4]– XeF4 trans-WCl2F4

12- Which statement is true about the change in symmetry on going from BF3 to [BF4]–? a) b) c) d) The point group changes from D3h to Td The point group changes from C3v to Td The point group changes from D3h to D4h The point group changes from D3h to C3v

Seleted Problems (from the text book):

1, 3, 4, 5, 6, 7, 8, 9, 12, 14, 15, 16, 17, 19, 20.