11 markeasy
In HPLC, the mobile and stationary phases are
| Mobile phase | Stationary phase | ||
|---|---|---|---|
| ☐ | A | gas | liquid |
| ☐ | B | gas | solid |
| ☐ | C | liquid | gas |
| ☐ | D | liquid | solid |
Choose your answer
Chemistry
Organic Analytical Techniques — Multiple-Choice Questions (Edexcel IAL Chemistry): Exam Questions
Exam code:YCH118 questions · 9 marks · ≈ 9 min
21 markmedium
The mass spectrum of the compound shown is obtained using a high resolution mass spectrometer.
What is the mass to charge ratio, m/ z, of the molecular ion of this compound?
[Ar values: H = 1.0078 C = 12.0000 O = 15.9949]
Choose your answer
92.0261
92.0312
93.0339
93.0390
32 marksmedium
(a)
This question is about chromatography.
A spot caused by an amino acid has moved 42 mm from the baseline of a paper chromatogram. The Rf value for the amino acid under these conditions is 0.62.
What is the distance moved by the solvent?
Choose your answer
680 mm
68 mm
42 mm
26 mm
(b)
In gas chromatography, GC, which of these would be the most suitable carrier gas?
Choose your answer
argon
hydrogen
methane
oxygen
41 markmedium
How many peaks are there in the carbon-13 (13C) NMR spectrum of methylcyclohexane?
Choose your answer
one
three
five
seven
51 markmedium
In gas chromatography, a gas containing a mixture is passed over a liquid stationary phase. The main reason a mixture is separated into its components is because they have different
Choose your answer
boiling temperatures
forces of attraction to the liquid
relative molecular masses
volatilities
61 markmedium
In the high resolution proton NMR spectrum of propan-2-ol, CH3CHOHCH3 there are
Choose your answer
one singlet, one doublet and a heptet
one singlet, two doublets and a heptet
two singlets and two triplets
three singlets and a quartet
71 markmedium
A mixture of organic compounds was analysed using thin-layer chromatography.
The Rf value was 0.92 for one of the components in the mixture.
What can be deduced about the attractions between that component and the stationary and mobile phases?
| Attraction between component and stationary phase | Attraction between component and mobile phase | ||
|---|---|---|---|
| ☐ | A | strong | strong |
| ☐ | B | strong | weak |
| ☐ | C | weak | weak |
| ☐ | D | weak | strong |
Choose your answer
81 markmedium
The infrared spectrum of an organic compound shows:
- a very broad absorption extending from approximately 2500 to 3300 cm⁻¹
- a sharp, strong absorption at approximately 1715 cm⁻¹
Which functional group is present in the compound?
Choose your answer
Alcohol
Aldehyde
Carboxylic acid
Ketone