DSP ONLINE BITS 4 UNIT VII

UNIT VII

Paper and Thin layer chromatography

1S. In paper chromatography, the ratio of distance traveled by the solute phase from the origin line to the distance

traveled by solvent from origin is defined as

a. R_f

b. R_x

c. R_m

d. R_c ans a

2M. The ratio of distance traveled by the substance from the origin line to the distance traveled by a standard

substance from the origin line is defined as

a. R_f

b. R_x

c. R_m

d. R_c ans b

3H. In chromatography according to Bate-Smith and Westall, R_m is defined as

a. R_m=log(R_f -1)

b. R_m=log(1/R_f -1)

c. R_m=exp(R_f -1)

d. R_m=1/R_f ans b

4S. _________ is also known as circular paper chromatography.

a. Ascending chromatography

b. Descending chromatography

c. Two dimensional chromatography

d. Radial chromatography ans d

5S. __________________ papers are used when substance to be separated have wide apart Rf values

a. Slow paper

b. Heavy paper

c. Thick paper

d. Coarse and faster paper. Ans d

6M. Surface chromatography is also known as ______________ chromatography.

a. Gas

b. TLC

c. Adsorption

d. Ion exchange ans b

7M. ________________- is used to separate acidic and neutral substances.

a. Silica gel

b. Alumina

c. Keisleguhr

d. Cellulose powder ans a

8S. ________________ is used as a binder to bind the adsorbent to glass plate in TLC

a. Silica gel

b. Zinc carbonate

c. Magnesium carbonate

d. Gypsum ans d

9H. The error which arises when the TLC chamber is not completely saturated with vapour and which result in

lack of reproducibility of Rf values is called

a. Edge effect

b. Vapour effect

c. Adsorbent effect

d. Chamber effect ans a

10S. The adsorbent in TLC is purified by a preliminary development with methanol and concentrated HCl since

it contains __________________ as impurity

a. Copper

b. Aluminium

c. Iron

d. Zinc ans c

Adsorption chromatography, gel filteration and affinity chromatography

1S. Seperation of component by adsorption chromatography depends upon

(i) degree of adsorption by adsorbent (ii) concentration of solute (iii) solubility in the solvent used for separation

a. (i) and(ii)

b. (i) and (iii)

c. (ii) and (iii)

d. (i), (ii) and (iii) ans d

2M. Langmuir adsorption isotherm relates mass of solute adsorbed per unit mass of adsorbent(m), and concentration

of solute(C) by the equation

a. m=(k₁k₂C)/(1+k₂C).

b. m=k₁k₂C(1+k₂C)

c. m=k₁C+k₂C

d. m=k₁C-K₂C ans a

3S. freundlich adsorption isotherm is given by the equation

a. m=K.C

b. m=KC^x

c. m=exp(KC)

d. m=KC^-x ans b

4M. ___________ is widely used for separation of proteins and nucleic acids

a. hydroxyapatite

b. silicic acid

c. magnesium carbonate

d. calcium carbonate ans a

5H. The strength of adsorption of polar groups on polar compounds increases in order

a. –CH=CH–, -OCH3 , =C=O, -COOR

b. –CH=CH–, -OCH3, -COOR, =C=O.

c. –COOR, -OCH3, –CH=CH–, =C=O

d. -OCH3, -COOR, –CH=CH–, =C=O ans b

6S. ___________ chromatography is also known as molecular sieve filtration.

a. Paper

b. Adsorption

c. Affinity

d. Gel permeation ans d

7S. which among the following is used for gel permeation.

a. Silica gel

b. Polyacrylamide

c. Magnesium carbonate

d. Keisleguhr ans b

8H. In gel permeation chromatography, the elution volume(Ve), void volume (Vo) distribution coefficient(K) and

volume inside the gel matrix (Vi) are related by the equation

a. Vo=Ve+KVi

b. Vi=KVo+Ve

c. Vi=KVe+Vo

d. Ve=Vo+KVi ans d

9S. _____________ chromatography separates molecules based on molecular shape and size

a. Gel permeation

b. Adsorption

c. Affinity

d. Gas ans a

10M. In adsorption chromatography, the adsorbent material is heated to 110oC to ___________

a. Activate the adsorbent

b. Deactivate the absorbent

c. Sterilize the adsorbent

d. Purify the adsorbent ans a

Ion exchange chromatography

1S. ________________ chromatography works on the attraction between oppositely charged particles.

a. Adsorption

b. Gel permeation

c. TLC

d. Ion exchange. ans d

2M. Cation exchangers possess __________ charged groups and these will attract _______ charged molecules.

a. Negative, positive.

b. Positive, positive

c. Neutral, both positive and negative

d. Neutral, only positive ans a

3S. ___________ are also known as basic ion exchange material

a. Cation exchanger

b. Anion exchanger.

c. Zeolites

d. Sephadex ans b

4H. The increasing order of affinity of ions in ion exchange chromatography is

a. Na⁺2+3+

b. Al³⁺2++

c. Ca2⁺+3+

d. Al³⁺+2+ ans a

5H. The increasing order of affinity for ion exchange among the following ions is

a. Be²⁺2+2+

b. Be²⁺2+2+.

c. Sn²⁺2+2+

d. Sn²⁺2+2+ ans b

6M. Cation exchanger is ____________ to which active ____________ are attached.

a. Polymeric cation, anions

b. Polymeric anion, cations.

c. Neutral, ions

d. Polymeric anion, anions ans b

7S. Zeolites exchange ___________ ions present in hard water for __________ ions.

a. Na⁺ and Ca²⁺, Mg²⁺

b. Na⁺ and K⁺, Al3⁺

c. Ca2⁺ and Mg²⁺, Na⁺.

d. K⁺, Mg²⁺ ans c

8S. Cation exchange resins contain which groups among the following?

a. Carboxylic groups.

b. Amine groups

c. Quarternary ammonium groups

d. Diazonium groups ans a

9S. Anion exchange resins contain which groups among the following

a. Carboxylic groups

b. Phenolic groups

c. Quarternary ammonium groups.

d. Sulphonic ans c

10M. The ion exchange capacity of anions is found to decrease in the order

a. PO₄^3->SO₄^2->I^-

b. I^-> SO₄^2-> PO₄^3-

c. SO₄^2->PO₄^3->I^-

d. PO₄^3->I^->SO₄^2- ans a

Gas Chromatography and chromatofocussing

1S. Gas chromatography uses ________ as mobile phase.

a. Liquid

b. Gas

c. Solid

d. Vacuum ans b

2S. The phenomenon in which a vapour or gas coming in contact with liquid dissolves in liquid follows the

equation _____________

a. Henry’s law of partition

b. Langmuir’s equation

c. Freundlich equation

d. Law of mass action ans a

3M. Henry’s law of partition can me mathematically stated as

a. x/m=K.C

b. x=KC/m

c. m=KCx

d. C=Kxm ans a

4M. In gas chromatography, the distribution coefficient(K) can be determined by which of the following equation?

a. K=(Tr-To)/To.

b. K.Tr=To

c. K-Tr=To

d. K=Tr-To ans a

5H. In a gas chromatography column, a gas c spends 20% of its time in liquid A and 80% of its time as a gas. If the

gas moves at the rate of 2ft/min, calculate the time required for the gas to pass a column of length 6ft.

a. 3.5 min

b. 4.5min

c. 3.75 min

d. 4 min ans c

6S. __________ gas is often used as a carrier gas in gas chromatography

a. Inert

b. Reactive

c. Liquefied

d. Mixture of ans a

7S. ___________ detector is used for detecting chlorinated pesticides.

a. Flame ionization

b. Electron capture.

c. Flame ionization

d. Flame emission ans b

8S. Flame ionization detectors are based on ________________

a. Temperature and resistance of wire

b. Electrical conductivity of gases.

c. Electron affinity of gases

d. Temperature difference ans b

9H. The separation factor(S) of two gases (a and b) is calculated by the equation

a. S=Ka+Kb

b. S=Ka/Kb

c. S=KaKb

d. S=Ka-Kb ans b

10M. Given the concentration of the gas in stationary phase(Xs) and concentration of gas in mobile phase(Xm)

the distribution coefficient is calculated by

a. K=XsXm

b. K=Xs-Xm

c. K=Xs/Xm

d. K=Xs+Xm ans c

HPLC AND FPLC

1M. Resolving power of a chromatographic column increases with increase in

a. Column length

b. Number of theoretical plates per unit length

c. Column length and number of theoretical plates per unit length.

d. Pumping speed ans c

2S. In HPLC, the resolution is increased by

a. Decreasing diffusion.

b. Increasing diffusion

c. Decreasing column length

d. Decreasing number of plates per unit length ans a

3S. In HPLC, the output is displayed in the form of a graph between

a. Absorbance and column length

b. Absorbance and retention time.

c. Pumping speed and retention time

d. Retention time and column length ans b

4S. In HPLC, the retention time increases with increase in _____________.

a. Column length.

b. Pumping speed

c. Absorbance

d. Sample volume ans a

5M. In liquid-liquid partition systems, the stationary phase

a. Is present in the form of liquid in a column

b. Is coated onto an inert support.

c. Is similar to mobile phase

d. Is present over a hydrolytically and thermally unstable material ans b

6H. In reverse phase chromatography, _________ compound is used as a stationary phase and _________

compound is used as a mobile phase.

a. Polar, polar

b. Poral, non-polar

c. Non-polar, Polar.

d. Non-polar, non-polar ans c

7H. In normal liquid-liquid chromatography, _____________ compound is used as stationary phase and _______

compound is used as mobile phase.

a. Polar, polar

b. Polar, non-polar

c. Non-polar, polar

d. Non-polar, non-polar ans b

8S. In a column consisting of pellicular support involves the reaction with reactive ___________ group present

on the silica gel

a. Phenol

b. Alcohol

c. Silanol

d. Alkyl nitrile ans c

9M. In van deemter equation { HETP= a+(B/u)+cu }, the term A represents

a. Longitudinal term

b. Eddy diffusion term.

c. Non-equilibrium in mass transfer terms

d. Adsorption term ans b

10S. in HPLC, the column selectivity depends upon _______________

a. Eddy diffusion

b. Partition coefficient.

c. Column length

d. Mobile phase ans b