Quiz 1 Session 1, Quiz 1 Session 2, Quiz 2 Session 1, Quiz 2
Session 2, Quiz 3 Session 1, Quiz 3 Session 2, Quiz 4 Session
1, Quiz 4 Session 2) Questions With Complete Solutions
A student dissolved a product in acetone and spotted on a silica
TLC plate to determine the purity of the product. A 2:1 mixture
of heptane:acetone was placed in the developing chamber.
[A] Silica is...
A1) Analyte
A2) Mobile phase
A3) Stationary phase
A3) Stationary phase
A student dissolved a product in acetone and spotted on a silica
TLC plate to determine the purity of the product. A 2:1 mixture
of heptane:acetone was placed in the developing chamber.
[B] The heptane/acetone mixture is...
B1) Analyte
B2) Mobile phase
B3) Stationary phase
B4) Solid
B5) Eluent
B2) Mobile phase
B5) Eluent
Given a TLC Plate
- - - (Solvent Front)
,-X-
X--
- - X (Origin)
ABC
[A] Order in terms of Polarity (Least polar to Most Polar)
a) A
b) B
c) C
b) B
a) A
c) C
Given a TLC Plate
- - - (Solvent Front)
-X-
X--
- - X (Origin)
ABC
[B] Why didn't C move from the baseline?
B1) C is strongly absorbed to the silica because of its polarity
B2) C is not soluble in the eluent
B3) C was not dissolved when spotted on the plate
B4) C in nonpolar, like the silica
B1) C is strongly absorbed to the silica because of its polarity
Given a TLC Plate
- - - (Solvent Front)
,-X-
X--
- - X (Origin)
ABC
Extract
- (Solvent Front)
X
X
- (Origin)
[C] What compounds are in the Extract?
a) A
b) B
c) C
a) A
b) B
What is true about the permanganate dip?
a) Permanganate enables the plate to fluoresce under UV light
b) Most of the plate turns pink because unreacted permanganate
is pink
c) If a compound has double bonds its TLC spot turns yellow
d) Permanganate reduces double bonds
e) None of these
b) Most of the plate turns pink because unreacted permanganate
is pink
c) If a compound has double bonds its TLC spot turns yellow
, What statement about gloves is true?
a) Most gloves protect against most chemicals
b) Only non-disposable gloves protect against most chemicals
c) No glove material protects against all chemicals
d) Latex gloves are the best choice for most people working in
lab
e) Gloves should be removed when they come in contact with
any hazardous chemical
c) No glove material protects against all chemicals
e) Gloves should be removed when they come in contact with
any hazardous chemical
What is true about gloves?
[A] Permeation
A1) Time for the first appearance of a chemical on the other side
of the glove
A2) Speed at which a chemical appears on the other side of the
glove
A3) Ability of a chemical to penetrate the glove material
through small pores
A4) Destructive change in the glove material
A3) Ability of a chemical to penetrate the glove material
through small pores
What is true about gloves?
[B] Degradation
B1) Time for the first appearance of a chemical on the other side
of the glove
B2) Speed at which a chemical appears on the other side of the