Deck 4: Separating Complex Mixtures

Question 1

Forensic Science labs rarely use mass spectrometry as a detector for gas chromatography.

Answer 1

False

Question 2

The procedure called liquid-liquid extraction is used to separate one solid material from another when at least two grams of material are present.

Answer 2

True

Question 3

The pH of pure water is 12.

Answer 3

False

Question 4

The p in pH stands for the positive logarithm of the concentration in moles per liter

Question 5

A solution with a pH of 13 is acidic.

Question 6

A solution with a pH of 5 is alkaline or base.

Question 7

Chemicals only have either negative or positive polarity.

Question 8

Polar substances that have actual, identifiable positive and negative ions are known as ionic substances.

Question 9

In order to effectively dissolve a solute in a solvent, both should be either polar or non-polar.

Question 10

Gas Chromatography is used for the separation of large amounts of solids or liquids.

Question 11

Gasoline and water dissolve readily in each other.

Question 12

Mass action refers to heavier molecules traveling slower through the column in chromatography than lighter molecules.

Question 13

The goal of chromatography is baseline resolution.

Question 14

The peak in a chromatogram is an oval shaped diagram.

Question 15

Gas chromatography can separate amounts of solids or liquids as small as a few nanograms.

Question 16

Electrophoresis is used to resolve problems in separation of substances that are very similar in nature when chromatography cannot be used.

Question 17

When a researcher has very little material (< 1 grams)to work with in identifying a substance, the most effective method to use to identify the substance is:

A) presumptive testing
B) liquid-liquid solution
C) chromatography
D) none of the above

Question 18

The two phases of chromatography are

A) liquid, solid
B) gas, solid
C) stationary, mobile
D) a and b only

Question 19

Gasoline contains over ___________ separate substances.

A) 100
B) 200
C) 300
D) 400

Question 20

The process used to describe the travel of the mobile phase through the stationary phase of TLC is known as:

A) caterpillar action
B) capillary action
C) vessel action
D) electrophoresis