Chromatography lab ACTUAL UPDATED
Exam Questions and CORRECT Answers
Chromatography is a powerful tool for _______ and _______ the components of a mixture -
CORRECT ANSWER - separating, examining
There are two phases: the ______ phase and the _________ phase - CORRECT
ANSWER - Mobile, stationary
What happens during the mobile phase? - CORRECT ANSWER - The mixture travels
across the stationary phase. The components interact with the stationary phase, getting absorbed.
Differences in the ________ means the amount of time they spend interacting with the stationary
phase and the distance travelled differs. - CORRECT ANSWER - structure of the
molecules
What is the stationary phase? - CORRECT ANSWER - Paper
What acts as the mobile phase? - CORRECT ANSWER - Solvents, eluent
As the eluent carries the mixture up the paper, you will see it_______ - CORRECT
ANSWER - separate into its different components
Each time you run a chromatography experiment, the distance the spots travel will depend on
_________ - CORRECT ANSWER - how long you run it for
A _______ factor is calculated and used to compare different runs - CORRECT
ANSWER - Retardation
, What is the retardation factor? - CORRECT ANSWER - The distance traveled by the
middle of the spot divided by the distance traveled by the solvent front
For any specific eluent-stationary phase system, the retardation factor of a specific component
should be a _____ - CORRECT ANSWER - constant
Color additives were initially used to make food ______ and to mask _________ - CORRECT
ANSWER - more visually appealing
poor-quality, inferior or imitation foods
In 1883, the US Department of Agriculture (USDA) Bureau of Chemistry began ________ the
food industry - CORRECT ANSWER - regulating
To propagate the food safety effort, in 1906 the USDA hired a consultant, _________, to
determine colorants that would be safe to consume in food - CORRECT ANSWER - Dr.
Bernard Hesse
In 1907, the number of synthetic food dyes approved for use in the US was reduced from
_______ to ______ - CORRECT ANSWER - 695 to 7
Only _____ of the original dyes from 1907 are still accepted for use today. _______ others were
added between 1907 and 1971. - CORRECT ANSWER - 2 of the original dyes
5 more were added
How many food dyes color all US food today? - CORRECT ANSWER -5
All of the FD&C-approved food dyes are _______, ___-soluble organic compounds that bind to
________ and ___________ in large food molecules, including proteins and carbs - CORRECT
ANSWER - charged, water-soluble
Bind to natural ionic and polar sites
Exam Questions and CORRECT Answers
Chromatography is a powerful tool for _______ and _______ the components of a mixture -
CORRECT ANSWER - separating, examining
There are two phases: the ______ phase and the _________ phase - CORRECT
ANSWER - Mobile, stationary
What happens during the mobile phase? - CORRECT ANSWER - The mixture travels
across the stationary phase. The components interact with the stationary phase, getting absorbed.
Differences in the ________ means the amount of time they spend interacting with the stationary
phase and the distance travelled differs. - CORRECT ANSWER - structure of the
molecules
What is the stationary phase? - CORRECT ANSWER - Paper
What acts as the mobile phase? - CORRECT ANSWER - Solvents, eluent
As the eluent carries the mixture up the paper, you will see it_______ - CORRECT
ANSWER - separate into its different components
Each time you run a chromatography experiment, the distance the spots travel will depend on
_________ - CORRECT ANSWER - how long you run it for
A _______ factor is calculated and used to compare different runs - CORRECT
ANSWER - Retardation
, What is the retardation factor? - CORRECT ANSWER - The distance traveled by the
middle of the spot divided by the distance traveled by the solvent front
For any specific eluent-stationary phase system, the retardation factor of a specific component
should be a _____ - CORRECT ANSWER - constant
Color additives were initially used to make food ______ and to mask _________ - CORRECT
ANSWER - more visually appealing
poor-quality, inferior or imitation foods
In 1883, the US Department of Agriculture (USDA) Bureau of Chemistry began ________ the
food industry - CORRECT ANSWER - regulating
To propagate the food safety effort, in 1906 the USDA hired a consultant, _________, to
determine colorants that would be safe to consume in food - CORRECT ANSWER - Dr.
Bernard Hesse
In 1907, the number of synthetic food dyes approved for use in the US was reduced from
_______ to ______ - CORRECT ANSWER - 695 to 7
Only _____ of the original dyes from 1907 are still accepted for use today. _______ others were
added between 1907 and 1971. - CORRECT ANSWER - 2 of the original dyes
5 more were added
How many food dyes color all US food today? - CORRECT ANSWER -5
All of the FD&C-approved food dyes are _______, ___-soluble organic compounds that bind to
________ and ___________ in large food molecules, including proteins and carbs - CORRECT
ANSWER - charged, water-soluble
Bind to natural ionic and polar sites
