CHEM 214 - Midterm 2013
Young Galley aka “The Coughdrop”
1. (7 marks) A detailed microstate analysis of the d2 electron configuration results in the terms: 1S, 3P, 1D, 3F, 1G a) Insert arrows (electrons) into the 5 atomic orbitals at the d-level in a manner consistent with each of the terms above.
b) Ignoring spin-orbit coupling (L-S, L+S), indicate which of the energy states above reflects the ground electronic state of the system (atom).
2. (10 marks) From DSC data, a globular protein displays a denaturation transition at 80°C with a peak area of 157 kJ mol-1. At 0°C 38% of the protein is in the denatured state. Calculate the ΔCp for the protein and the temperature at which the fraction of the protein in the denatured form would be at a minimum.
3. (10 marks) The term "activation" is employed by chemists in reference to two very distinct processes. Provide examples (preferably biochemical) of those two uses, being sure to emphasize the fundamental physical chemical principles associated with each.
4. (8 Marks) Consider the two (ls,2s) wavefunctions below: 1
2 1 2
[Ψ1𝑠 (1)Ψ2𝑠 (2) + Ψ1𝑠 (1)Ψ2𝑠 (2)][α(1)β(2)-α(2)β(1)]
[Ψ1𝑠 (1)Ψ2𝑠 (2) − Ψ1𝑠 (2)Ψ2𝑠 (1)][α(1)β(2)+α(2)β(1)]
Indicate the following:
a) The basic difference between the wavefunctions wrt to spin and energy.
b) The presence of 4 spin- and 4 space-terms, rather than 2 in each case?
5. (10 marks) What fraction of an electronic charge is present on the O-atom in H2O? Given: μ=1.85D, rO-H = 0.96 A, H-O-H bond angle = 104.5°
(b) Calculate the ionic character for H2O
6. The C-C bonds in benzene all have the same bond lengths due to resonance. Explain how the stability of the benzene ring is enhanced. (Use the Virial Theorem).
8. (10 marks – option 2) The contribution of a vibration to EThermal assuming it behaves as a harmonic oscillator, can be obtained for 1 mole of vibrations by summing up the energies over the energy levels yielding:
(a) Differentiate the equation wrt temperature to obtain an expression for the contribution to the Cv of a molecule.
(b) Show that the contribution to the Cv reduces to R for kT >> hv.
1. (7 marks) A detailed microstate analysis of the d2 electron configuration results in the terms: 1S, 3P, 1D, 3F, 1G a) Insert arrows (electrons) into the 5 atomic orbitals at the d-level in a manner consistent with each of the terms above.
b) Ignoring spin-orbit coupling (L-S, L+S), indicate which of the energy states above reflects the ground electronic state of the system (atom).
2. (10 marks) From DSC data, a globular protein displays a denaturation transition at 80°C with a peak area of 157 kJ mol-1. At 0°C 38% of the protein is in the denatured state. Calculate the ΔCp for the protein and the temperature at which the fraction of the protein in the denatured form would be at a minimum.
3. (10 marks) The term "activation" is employed by chemists in reference to two very distinct processes. Provide examples (preferably biochemical) of those two uses, being sure to emphasize the fundamental physical chemical principles associated with each.
4. (8 Marks) Consider the two (ls,2s) wavefunctions below: 1
2 1 2
[Ψ1𝑠 (1)Ψ2𝑠 (2) + Ψ1𝑠 (1)Ψ2𝑠 (2)][α(1)β(2)-α(2)β(1)]
[Ψ1𝑠 (1)Ψ2𝑠 (2) − Ψ1𝑠 (2)Ψ2𝑠 (1)][α(1)β(2)+α(2)β(1)]
Indicate the following:
a) The basic difference between the wavefunctions wrt to spin and energy.
b) The presence of 4 spin- and 4 space-terms, rather than 2 in each case?
5. (10 marks) What fraction of an electronic charge is present on the O-atom in H2O? Given: μ=1.85D, rO-H = 0.96 A, H-O-H bond angle = 104.5°
(b) Calculate the ionic character for H2O
6. The C-C bonds in benzene all have the same bond lengths due to resonance. Explain how the stability of the benzene ring is enhanced. (Use the Virial Theorem).
8. (10 marks – option 2) The contribution of a vibration to EThermal assuming it behaves as a harmonic oscillator, can be obtained for 1 mole of vibrations by summing up the energies over the energy levels yielding:
(a) Differentiate the equation wrt temperature to obtain an expression for the contribution to the Cv of a molecule.
(b) Show that the contribution to the Cv reduces to R for kT >> hv.
