Spectroscopy
Consider the compounds A-D.
A B C D
Which compound(s), if any, can be distinguished from the others by:
i) Their UV-VIS spectra
Justify your choice
ii) The molecular ion observed in their mass spectra
Justify your choice
iii) Their IR spectra
Justify your choice
iv) The number of signals > 100ppm in the H-decoupled C-NMR
Justify your choice
b) Compound ____ has a H-NMR signal at δ2.5, which is split into 2 lines.
Justify your answer by stating why the signal is δ2.5 and why it is split into 2 lines.
Kinetics
, Glow sticks rely on the chemical phenomenon chemiluminescence, in which light is a
product of a reaction that can be started by bending the glow stick. Junius is preparing for a
mean outdoor party limited to 10 people in Palmerston North, where the expected night-time
temperature is 9°C. He has bought some expensive glow sticks, and wants to know how
long they will glow for.
He knows that his glow sticks can last 6 hours in Auckland, at a temperature of 19°C, and
thanks to Google, that the activation of the chemiluminescence reaction is 54.6kJ mol-1.
i) Can Junius reasonably expect his glow sticks to glow for longer in Palmy than Auckland?
Justify
ii) Calculate the ratio k2/k1 of the rate constants for the chemiluminescence reactions at the
two temperatures. (R = 8.314J K-1 mol-1, 0°C = 273K)
iii) Approximately how long will the glow sticks be able to glow at the Palmy party, if the
temperature prediction there is correct?
Justify
Reactions
Compound M is a 2° alkyl halide and has the molecular formula C5H11Br.
i) Draw the 3 possible constitutional isomers consistent with this information.
Consider the compounds A-D.
A B C D
Which compound(s), if any, can be distinguished from the others by:
i) Their UV-VIS spectra
Justify your choice
ii) The molecular ion observed in their mass spectra
Justify your choice
iii) Their IR spectra
Justify your choice
iv) The number of signals > 100ppm in the H-decoupled C-NMR
Justify your choice
b) Compound ____ has a H-NMR signal at δ2.5, which is split into 2 lines.
Justify your answer by stating why the signal is δ2.5 and why it is split into 2 lines.
Kinetics
, Glow sticks rely on the chemical phenomenon chemiluminescence, in which light is a
product of a reaction that can be started by bending the glow stick. Junius is preparing for a
mean outdoor party limited to 10 people in Palmerston North, where the expected night-time
temperature is 9°C. He has bought some expensive glow sticks, and wants to know how
long they will glow for.
He knows that his glow sticks can last 6 hours in Auckland, at a temperature of 19°C, and
thanks to Google, that the activation of the chemiluminescence reaction is 54.6kJ mol-1.
i) Can Junius reasonably expect his glow sticks to glow for longer in Palmy than Auckland?
Justify
ii) Calculate the ratio k2/k1 of the rate constants for the chemiluminescence reactions at the
two temperatures. (R = 8.314J K-1 mol-1, 0°C = 273K)
iii) Approximately how long will the glow sticks be able to glow at the Palmy party, if the
temperature prediction there is correct?
Justify
Reactions
Compound M is a 2° alkyl halide and has the molecular formula C5H11Br.
i) Draw the 3 possible constitutional isomers consistent with this information.
