Deck 18: Chemical Analysis: Characterizing Chemical Compounds

Question 1

A chromatographic technique features which two of the following?

A) Liquid phase
B) Stationary phase
C) Mobile phase
D) Gas phase
E) Solid phase

Answer 1

B,C

Question 2

Match the size of the following compounds with the order in which they are collected during molecular exclusion chromatography.
-Large

A) First
B) Second
C) Thired

Answer 2

A

Question 3

Match the size of the following compounds with the order in which they are collected during molecular exclusion chromatography.
-Medium

A) First
B) Second
C) Thired

Answer 3

B

Question 4

Match the size of the following compounds with the order in which they are collected during molecular exclusion chromatography.
-Small

A) First
B) Second
C) Thired

Question 5

Which of the following statements regarding chromatography are true? Select all that apply.

A) The mobile phase may be a liquid or a gas.
B) The stationary phase is always a solid.
C) Separation on the basis of size is called affinity chromatography.
D) The fluid exiting the column is called the eluent.
E) During chromatography, the mobile phase passes over the stationary phase.

Question 6

The length of time a compound takes to pass through a chromatographic column is called which one of the following?

A) The holding time
B) The release time
C) The repulsion time
D) The retention time
E) The separation time

Question 7

Which two of the following statements correctly describe gas-liquid chromatography?

A) The mobile phase is a liquid.
B) The mobile phase is a gas.
C) The stationary phase is a solid.
D) The stationary phase is a liquid.
E) The stationary phase is a gas.

Question 8

Rank the size of the following compounds according to the distance they travel through a gel during electrophoresis, with 1 = travels the furthest distance; 3 = travels the shortest distance.

Question 9

Match the following techniques with the attributes they exploit to effect separation.
-Isoelectric focusing

A) Electrical charge
B) Electrical charge and size
C) Size

Question 10

Match the following techniques with the attributes they exploit to effect separation.
-2D-PAGE

A) Electrical charge
B) Electrical charge and size
C) Size

Question 11

Match the following techniques with the attributes they exploit to effect separation.
-SDS-PAGE

A) Electrical charge
B) Electrical charge and size
C) Size

Question 12

Which of the following statements about mass spectrometry is true?

A) The species being studied by mass spectrometry must carry a negative charge.
B) Mass spectrometry usually generates a mass spectrum with a single peak.
C) The molecular ion peak in a mass spectrum can be used to distinguish between structural isomers.
D) The sample being studied by mass spectrometry must be a vapour.
E) Isotopes of the same element generate the same peak in a mass spectrum.

Question 13

The position of a peak in a ¹³C-NMR spectrum tells us information about which of the following?

A) The molecular mass of the sample being studied.
B) The atoms immediately surrounding a carbon atom.
C) The number of carbon atoms present in the sample.
D) The electrical charge carried by the sample.
E) The 3D structure of the sample being studied.

Question 14

Which of the following statements about NMR spectroscopy are true? Select all that apply.

A) The area under a peak in an NMR spectrum tells us about the number of atoms experiencing the same chemical environment.
B) NMR spectroscopy can be used to tell us about any elements in a compound.
C) An NMR spectrum tells us about the different isotopes of an element that are present in a compound.
D) NMR spectroscopy exploits light in the radiofrequency region of the electromagnetic spectrum.

Question 15

Which of the following bonds vibrates at the highest frequency in an infrared spectrum? (Carbon has an atomic mass of 12; oxygen has an atomic mass of 16; hydrogen has an atomic mass of 1.)

A) C-H
B) O-H
C) C-O
D) C-C
E) O-O

Question 16

Rank the following bonds according to the wavelength of infrared light that they absorb, with 1 being the shortest wavelength, and 3 being the longest wavelength.

Question 17

Rank the following wavenumbers according to the energy they represent, with 1 = highest energy, and 3 = lowest energy.

Question 18

Rank the following wavelengths according to the energy they represent, with 1 = highest energy, and 3 = lowest energy.

Question 19

Match the techniques with the characteristics that they can be used to reveal.
-Mass of the sample

A) Mass spectrometry
B) X-ray crystallography
C) Infrared spectroscopy
D) NMR spectroscopy

Question 20

Match the techniques with the characteristics that they can be used to reveal.
-3-D structure

A) Mass spectrometry
B) X-ray crystallography
C) Infrared spectroscopy
D) NMR spectroscopy

Question 21

Match the techniques with the characteristics that they can be used to reveal.
-Identity of functional groups attached to the hydrocarbon framework

A) Mass spectrometry
B) X-ray crystallography
C) Infrared spectroscopy
D) NMR spectroscopy

Question 22

Match the techniques with the characteristics that they can be used to reveal.
-Nature of the hydrocarbon framework

A) Mass spectrometry
B) X-ray crystallography
C) Infrared spectroscopy
D) NMR spectroscopy

Question 23

Which of the following is not a type of bond vibration?

A) Wag
B) Scissor
C) Bend
D) Twist
E) Stretch

Question 24

The parts of a compound that absorb strongly when exposed to ultraviolet light are called which of the following?

A) Chlorophylls
B) Chromatids
C) Chromophores
D) Chloroplasts
E) Photons

Question 25

A compound has a distribution ratio of 0.67. When mixed with organic and aqueous solvents, and the mixture allowed to settle, the compound is most likely to partition into the organic phase.

Question 26

Centrifugation separates solid matter from the fluid in which it is suspended. What is the fluid called?

A) Solvent
B) Solute
C) Eluent
D) Sediment
E) Supernatant