Salad Quiz 15

The structure of 2-chloropropane and propan-2-ol are analysed separately using low resolution nuclear magnetic resonance spectroscopy (NMR). Which of the following statements best describes the ¹H NMR spectra produced for each of the molecules?

• The spectra for 2-chloropropane and propan-2-ol are identical in appearance.
• The spectra for 2-chloropropane and propan-2-ol each have two main peaks.
• The spectrum for 2-chloropropane has two main peaks whereas the spectrum for propan-2-ol has three main peaks.
• The spectrum for 2-chloropropane has three main peaks whereas the spectrum for propan-2-ol has four main peaks.

Which one of the following compounds will include absorption bands in the infra-red spectrum at about 1700 cm^-1 and 2600 cm^-1?

• pentane
• pentan-2-ol
• pentanoic acid
• pent-2-ene

When a molecule absorbs radio waves during nuclear magnetic resonance spectroscopy (NMR) this is most likely to lead to

• the molecule moving to a higher vibrational energy level
• a deflection in the path taken by the molecule when it is travelling at high speeds
• an electron being promoted from a lower energy level to a higher energy level
• a change in the spin state of nucleons

A solution calorimeter was inadvertently calibrated with 105 mL of water instead of 100 mL. The calorimeter was emptied and dried and then used to determine the heat of reaction of powdered zinc in 100 mL of HCl (aq). It can be deduced from this information that the correct calibration factor should be

• Lower and the heat of reaction should be lower.
• Higher and the heat of reaction should be higher.
• Lower and the heat of reaction should be higher.
• Higher and the heat of reaction should be lower.

The diagram shown depicts a possible reaction pathway for producing an ester which has a distinctly pineapple odour. 
Comparison of the ¹³C NMR spectra and low resolution ¹H NMR of compound Y would show?

• More peaks on the ¹³C NMR spectrum
• Fewer peaks on the ¹³C NMR spectrum.
• The same number of peaks on both spectra.
• TMS at a lower chemical shift on the ¹H spectrum.

The diagram shown depicts a possible reaction pathway for producing an ester which has a distinctly pineapple odour. 
How many of the organic compounds in this reaction pathway would be expected to show a strong absorption band between 3200 and 3550 cm^-1 in their IR spectra

• 1
• 2
• 3
• 4

The diagram shown depicts a possible reaction pathway for producing an ester which has a distinctly pineapple odour. 
At what m/e ratio would the molecular ion be expected to appear in the mass spectrum of the ester produced via this reaction pathway?

• 88
• 102
• 106
• 120

A galvanic cell is established to power a torch, as shown.
For this cell, the overall equation will be

• 2Al(s)+3H_2(g)→2Al³⁺(aq)+6H⁺(aq)
• 3Cl^-(aq)+Al(s)→AlCl₃(aq)
• 2Al³⁺(aq)+3H_2(g)→2Al(s)+6H⁺(aq)
• 2Al(s)+6H⁺(aq)→2Al³⁺(aq)+3H₂(g)

Tags

NGSS.HS-PS1-4

NGSS.HS-PS1-2

NGSS.HS-PS1-7

A galvanic cell is established to power a torch, as shown.
For this cell, the

• electrons will flow from the aluminium to the hydrogen half-cell
• aluminium electrode will be the positive anode
• concentration of aluminium ions in solution will be falling
• hydrogen half-cell will be the negative cathode

The ratio of the peak areas in the ¹H NMR spectrum of 2-methylpropane is?

• 1:9
• 1:3:3:3
• 1:3:6
• 2:5