# Solutions

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

1. Using the alphabet, answer the following:
a) how many letters have a mirror plane? 26
b) how many letters have more than one mirror plane? 15
c) how many letters have a rotational axis? 17
d) which letter has the highest ordered rotational axis? I (assuming cylinder) or (O assuming circle)
e) which letters have an inversion center? H, I, N, O, S, X, Z

2. Determine all of the symmetry elements in each of the following:

 your left shoe E eclipsed ethane E, C3, 3C2,sh, 3sv, S3 Fe(CO)5 E, C3, 3C2, sh, 3sv, S3 CHF3 E, C3, 3sv CF2H2 E, C2, 2sv CFH3 E, C3, 3sv IBr4+ E, C2, 2sv COS E, Cinf, inf sv IBr4- E, C4, 4C2, sh, 4sv, i, S4 SO2 E, C2, 2sv HF E, Cinf, inf sv F2 E, Cinf, inf C2, sh, inf sv, i, Sinf BFCl2 E, C2, 2sv BFClBr E, sh CoCl3(OH2)- E, C3, 3sv Cu(CN)3 E, C3, 3C2, sh, 3sv, S3

inf = infinity

3. Determine the point group for each of the following:(point group flow chart)

 SF6 Oh eclipsed ethane D3h CH4 Td CHF3 C3v CF2H2 C2v CFH3 C3v IBr4+ C2v COS Cinfv IBr4- D4h SO2 C2v HF Cinfv F2 Dinfh BFCl2 C2v BFClBr Cs CoCl3(OH2)- C3v Cu(CN)3 (planar) D3h Ni(CO)4 Td Fe(CO)5 D3h your left shoe C1 a round doorknob Cinfv

inf = infinity