Question 1

A chromatographic technique features which two of the following?

Accepted Answer

B,C

Question 2

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

Accepted Answer

In molecular exclusion chromatography, also known as size-exclusion chromatography, larger molecules are eluted first because they cannot enter the pores of the stationary phase and thus travel a shorter path through the column.

Question 3

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

Accepted Answer

B

Question 4

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

Accepted Answer

In molecular exclusion chromatography, also known as size-exclusion chromatography, smaller molecules are collected last because they enter the pores of the stationary phase and take longer to elute.

Question 5

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

Accepted Answer

The answer of Which of the following statements regarding chromatography...

Question 6

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

Accepted Answer

The retention time is the time it takes for a compound to travel through the chromatographic column to the detector.

Question 7

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

Accepted Answer

In gas-liquid chromatography, the mobile phase is a gas, and the stationary phase is a liquid coated on a solid support.

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.

Accepted Answer

The answer of Rank the size of the following compounds...

Question 9

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

Accepted Answer

Isoelectric focusing separates molecules based on their isoelectric point, which is determined by their electrical charge.

Question 10

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

Accepted Answer

2D-PAGE (Two-Dimensional Polyacrylamide Gel Electrophoresis) separates proteins based on two attributes: isoelectric point (electrical charge) and molecular weight (size).

Question 11

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

Accepted Answer

SDS-PAGE separates proteins based on their size. SDS (sodium dodecyl sulfate) denatures proteins and gives them a uniform negative charge, allowing them to be separated by size during electrophoresis.

Question 12

Which of the following statements about mass spectrometry is true?

Accepted Answer

The answer of Which of the following statements about mass...

Question 13

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

Accepted Answer

The position of a peak in a ¹³C-NMR spectrum provides information about the chemical environment of a carbon atom, specifically the atoms immediately surrounding it, due to the shielding or deshielding effects they cause.

Question 14

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

Accepted Answer

The area under a peak in an NMR spectrum is proportional to the number of nuclei (usually hydrogen or carbon) in that environment. NMR spectroscopy uses radiofrequency radiation to induce transitions between nuclear spin states.

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.)

Accepted Answer

The frequency of a bond vibration is inversely proportional to the square root of the reduced mass of the atoms involved. The reduced mass is calculated as:Reduced mass = (Mass of atom 1 * Mass of atom 2) / (Mass of atom 1 + Mass of atom 2)For the C-H bond, the reduced mass is (12 * 1) / (12 + 1) = 11/13.For the O-H bond, the reduced mass is (16 * 1) / (16 + 1) = 15/17.For the C-O bond, the reduced mass is (12 * 16) / (12 + 16) = 192/28 = 64/7.For the C-C bond, the reduced mass is (12 * 12) / (12 + 12) = 144/24 = 6/1.For the O-O bond, the reduced mass is (16 * 16) / (16 + 16) = 256/32 = 8/1.The reduced mass of the C-H bond is the smallest, which means that the C-H bond will vibrate at the highest frequency.

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.

Accepted Answer

The answer of Rank the following bonds according to the...

Question 17

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

Accepted Answer

The answer of Rank the following wavenumbers according to the...

Question 18

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

Accepted Answer

The answer of Rank the following wavelengths according to the...

Question 19

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

Accepted Answer

Mass spectrometry is a technique used to determine the mass-to-charge ratio of ions, which can be used to calculate the mass of the sample.

Question 20

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

Accepted Answer

X-ray crystallography is a technique that can be used to reveal the 3-D structure of a molecule.

Quiz 18: Chemical Analysis: Characterizing Chemical Compounds

A chromatographic technique features which two of the following?

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

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

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

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

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

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

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.

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

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

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