# 5.6: Solutions for Selected Problems

- Page ID
- 190036

__Exercise 5.1.1:__

a) 0 b) 3- c) 3- d) 3+ e) 5+

__Exercise 5.1.2:__

a) O_{2} b) NO_{2}^{-} c) 2 e^{-}

__Exercise 5.3.1:__

- S: \(4 \times 2^{-} = 8^{-}\); Fe: \(2 \times 2^{+} + 2 \times 3^{+} = 10^{+}\); total \(= 2^{+}\)
- S: \(4 \times 2^{-} = 8^{-}\); Fe: \(1 \times 2^{+} + 2 \times 3^{+} = 8^{+}\); total \(= 0\)
- S: \(2 \times 2^{-} = 4^{-}\); Fe: \(2^{+} + 2^{+} = 5^{+}\); total \(=1^{+}\)

__Exercise 5.3.2:__

__Exercise 5.3.3:__

__Exercise 5.3.4:__

__Exercise 5.4.1:__

d) As the Fe becomes more reduced, the N-N stretching frequency decreases. That's because the more electron density there is on the Fe, the more it is able to backbond to the N_{2} (N_{2} is a π acceptor).