The physical separation of mixtures into individual components is..
chromatography
opacity
latent
trace evidence
2. Multiple Choice
30 seconds
1 pt
Two or more substances that are mixed together but not chemically combined is a ___
compound
mixture
keratin
chromatography
3. Multiple Choice
20 seconds
1 pt
Two or more substances that are chemically combined is a ___
compound
mixture
solvent
solute
4. Multiple Choice
20 seconds
1 pt
Ink can be separated by a method of -----------------------------------------------
distillation
filtration
chromatography
sedimentation
5. Multiple Choice
20 seconds
1 pt
chromatography separates the mixture of dyes on the basis of their ----------------------------
density
solubility
gravity
boiling point
6. Multiple Choice
20 seconds
1 pt
On the chromatogram given -------------- is mixture.
red
orange
green
black
7. Multiple Choice
30 seconds
1 pt
A pure substance shows ------------------ spot on chromat gram
0
1
2
3
8. Multiple Choice
20 seconds
1 pt
The diagram below shows a chromatogram obtained when a sample X was analysed together with four other known dyes P, Q, R and S. Dye Q was known to cause cancer. Which of the following dye(s) is/are safe for use?
P only
S only
P and S
P and X
9. Multiple Choice
45 seconds
1 pt
The diagram shows the chromatogram for three colouring dyes and that for a brown marker. What dye(s) are contained in the marker's ink?
purple and green
purple and yellow
purple only
green and yellow
10. Multiple Choice
45 seconds
1 pt
Dyes in water soluble markers may be separated by means of..
crystallization
sublimation
chromatography
sedimentation
11. Multiple Choice
30 seconds
1 pt
In Chromatography the retardation factor Rf are used for identification of components. A high Rf and a low Rt (retention time) mean the component has a
greater affinity to the stationary phase in both TLC and HPLC.
greater affinity to the stationary phase in TLC but a greater affinity for the mobile phase in HPLC
greater affinity to the mobile phase in TLC but a greater affininty for the stationary phase in HPLC
greater affinity to the mobile phase in both TLC and HPLC
12. Multiple Choice
30 seconds
1 pt
In Chromatography the retardation factor Rf are used for identification of components. A low Rf and a high Rt (retention time) mean the component has a
greater affinity to the stationary phase in both TLC and HPLC.
greater affinity to the stationary phase in TLC but a greater affinity for the mobile phase in HPLC
greater affinity to the mobile phase in TLC but a greater affininty for the stationary phase in HPLC
greater affinity to the mobile phase in both TLC and HPLC
13. Multiple Choice
30 seconds
1 pt
In Chromatography the retardation factor Rf are used for identification of components. A low Rf and a low Rt (retention time) mean the component has a
greater affinity to the stationary phase in both TLC and HPLC.
greater affinity to the stationary phase in TLC but a greater affinity for the mobile phase in HPLC
greater affinity to the mobile phase in TLC but a greater affininty for the stationary phase in HPLC
greater affinity to the mobile phase in both TLC and HPLC
14. Multiple Choice
30 seconds
1 pt
A student extracts the colour from some green smarties and uses paper chromatography to separate components colours. She finds blue has a Rf =0.38 and yellow Rf =0.75 this suggests
the yellow is more strongly adsorbed onto the stationary phase and is less solublein the mobile phase.
the yellow is more strongly adsorbed onto the stationary phase and is more soluble in the mobile phase.
the blue is more strongly adsorbed onto the stationary phase and is less solublein the mobile phase.
the blue is more strongly adsorbed onto the stationary phase and is less solublein the mobile phase.
15. Multiple Choice
30 seconds
1 pt
A high Rf value indicates strong
strong affinity to the stationary phase
strong affinity to the mobile phase
no affinity to the stationary phase
no affinity to the stationary phase
16. Multiple Choice
30 seconds
1 pt
A chromatography experiment uses water as a mobile phase. Which of the following would have the highestRf value
ethanol
propanol
butanol
pentanol
17. Multiple Choice
30 seconds
1 pt
A non polar stationary phase is used in HPLC. Which of the following would have the longest retention time.