Skip to main content
Chemistry LibreTexts

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.

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