# Homework 19 (Due 5/25/2016)

- Page ID
- 47403

Name: ______________________________

Section: _____________________________

Student ID#:__________________________

## Q19.1

\(CO_2\) is experimentally determined to be diamagnetic. If a student proposed the following structure to explain. Is a valid Lewis diagram? Does this Lewis diagram predict a diamagnetic species and if not, why?

## Q19.2

Does \(\ce{Br_2C=CHBr}\) have a dipole moment?

## Q19.3

What is the value of \(\psi^2_g\) (The probability density of finding the electron) at either nucleus in \(Li^+_2\) using the below equation for \(\psi_g\) ? What is the value of \(\psi^2_g\) at the midpoint of the bond? Use \(R_e =106\; pm \) and \(S = 0.86\)

\[\psi_g = \dfrac{1}{\sqrt{2(1+S)}}(1s_a + 1s_b) \]

The hydrogenic radial function of a 1s orbital is

\[R_{1,0} (r) = 2 \left(\dfrac{Z}{a_o}\right)^{3/2} e^{-\frac{Zr}{a_o}} \]

with the angular wave function (in this case \(Y_{0,0}\))

\[Y_{0,0} = \dfrac{1}{\sqrt{4\pi}} \]

## Q19.4

The first excited states of \(H_2^-\) are formed by exciting an electron from the antibonding \(1\sigma_u\) molecular orbital to the bonding \(2\sigma_g\) orbital. Write the electron configuration of the ground state and excited-state \(H_2^-\) molecules. What is the bond order of \(H_2^-\) in both states? Is \(H_2^-\) diamagnetic or paramagentic in either state?

## Q19.5

Which two second row homonuclear diatomic molecules do not follow conventional Molecular Orbital energy levels of the other second row homonuclear diatomic? Which are they and what is the difference?

## Q19.6

A excited state of \(O_2^*\) is formed by exciting a single electron in \(O_2\) from the molecular orbital \(1\pi_g\) to the orbital \(3\sigma_u\). Note that \(^*\) is used to represent an excited state species, not an antibonding molecular orbital.

- Write the electron configuration.
- What is the bond order of \(O_2^*\)?