ANALYTICAL CHEMISTRY II

1. The possible transitions for water molecule in UV-visible region are

 

a. σ→σ *, n→π *

 

b. n → σ*

 

c. σ →σ *

 

d. n→π *, π→π *

 

Correct Option: b

 

 

2. Choose the right statement

 

a. Cisoid shows less intense absorption

 

b. Exocyclic double bond causes a bathochromic shift of 30 n

 

c. The base value of transoid is 214 nm

 

d. Homoannular diene is called as transoid

 

Correct Option: c

 

 

3. Select the wavelength range corresponding to UV-visible region.

 

a. 200-800nm

 

b. 400-800 nm

 

c. 800-1200nm

 

d. none

 

Correct Option: a

 

 

4. Which of the following is a real limitation to Beer’s law

 

a. Analyte Dissociation

 

b. Polychromatic radiation is used as source

 

c. Analyte at high concentrations

 

d. Fluorescence

 

Correct Option: c

 

 

5. Which of the following statement is not correct ?

 

a. Absorptivity is a constant and depends on the nature of the molecule

 

b. Absorptivity changes with the intensity of the light

 

c. Absorbance is independent of intensity of the light

 

d. Absorbance has no units

 

Correct Option: b

 

 

6. Dynodes are present in

 

a. Phototube

 

b. Diode array

 

c. Photomultiplier tube

 

d. Barrier layer detector

 

Correct Option: c

 

 

7. In phototube, photo multiplier tube, the transmitted light from the cells produces photocurrent by falling on

 

a. Metal junction

 

b. Metal layer

 

c. Photocathode

 

d. Photoanode

 

Correct Option: c

 

 

8. Cut off wave length is the wavelength

 

a. Above which a analyte absorbs too much radiation

 

b. Below which a solvent absorbs too much radiation

 

c. Above which a solvent absorbs too much radiation

 

d. Below which an analyte absorbs too much radiation

 

Correct Option: b

 

 

9. The types of transitions possible in UV-visible region for a compound with molecular formula C 2H 4 are

 

a. sigma to pi

 

b. pi to pi*,

 

c. N to sigma star

 

d. sigma to sigma

 

Correct Option: b

 

 

10. phenol loses one proton and exists as phenoxide anion as shown below. Select the correct statement regarding their absorption.

 

a. Phenoxide  shows more absorption than phenol

 

b. Phenol has equal absorption as phenoxide anion

 

c. Phenol shows more absorption than phenoxide anion

 

d. none of them

Correct Option: a

 

 

11. Choose the right statement

 

a. Homoannulardiene is called as transoid

 

b. Exocyclic double bond causes a bathochromic shift of 30 n

 

c. The base value of transoid is 214 nm

 

d. Cisoid shows less intense absorption

 

Correct Option: c

 

 

12. Which of the following absorbs at more wavelength

 

a. aniline

 

b. benzene

 

c. phenol

 

d. ALL SHOWS EQUAL ABSORPTION

 

Correct Option: a

 

 

13. Which of the following statement is not correct ?

 

a. Absorptivity changes with the intensity of the light

 

b. Absorbance has no units

 

c. Absorbance is independent of intensity of the light

 

d. Absorptivity is a constant and depends on the nature of the molecule

 

Correct Option: a

 

 

14. All of the following are useful as a source for UV-Visible, EXCEPT

 

a. TUNGSTEN LAMP

 

b. globar source

 

c. xenon discharge lamp

 

d. duetrium discharge lamp

 

Correct Option: b

 

 

15. Absorption spectra is a plot of

 

a. % T Vs Concentration

 

b. Absorbance Vs wavelength

 

c. Absorbance Vs Concentration

 

d. % T Vs Wavelength

 

Correct Option: b

 

 

16. The intensity of an absorption band is always proportional to which of the following factor?

 

a. Molecular population of the initial state

 

b. Temperature

 

c. Molecular population of the final state

 

d. Atomic population

 

Correct Option: a

 

 

17. 1,3,5-hexatriene. Calculate it’s l max .

 

a. 184nm

 

b. 247nm

 

c. 254nm

 

d. 154

 

Correct Option: b

 

 

18. Which of the following shows bathochromic shift in polar solvent

 

a. ethylene

 

b. water

 

c. alcohol

 

d. chloroform

 

Correct Option: a

 

 

19. Which of the following leads to chemical deviation from Beer’s law

 

a. Change in pH of the solution

 

b. change in refractive index

 

c. polychromatic radiation

 

d. both a and b

 

Correct Option: a

 

 

20. WHICH OF The following radiations are weakest in energy?

 

a. visible

 

b. microwave

 

c. X rays

 

d. UV

 

Correct Option: b

 

 

21. Which of the following color has highest energy?

 

a. violet

 

b. red

 

c. blue

 

d. green

 

Correct Option: c

 

 

22. Which of the following material is used to coat the cathode in photo tube

 

a. Cesium

 

b. tungsten

 

c. zinc

 

d. all

 

Correct Option: a

 

 

23. Which of the following is a non-dispersive wavelength selector

 

a. filters

 

b. Gratings

 

c. PRISMS

 

d. CHOPPER

 

Correct Option: a

 

 

24. Dimerization of the sample produces

 

a. No effect

 

b. Hypsochromic shift

 

c. Bathochromic shift

 

d. Absence of absorbance

 

Correct Option: c

 

 

25. Dark current in photo multiplier tube is

 

a. The residual current that appears after the removal of incident light

 

b. The current due to spontaneous discharge of dynodes

 

c. The current produced by falling light on anode

 

d. The current produced by falling light on cathode

 

Correct Option: b

 

 

26. Diffraction gratings work on the basis of

 

a. Beer’s law

 

b. Max-Well Boltzman’s equation

 

c. Bragg’s equation

 

d. Noise-whitney equation

 

Correct Option: c

 

 

27. Which of the following spectroscopic region is just above the region in which we see?

 

a. microwave

 

b. laser

 

c. IR

 

d. visible

 

Correct Option: c

 

 

28. Electronic excitation are studied using

 

a. uv

 

b. visible

 

c. IR

 

d. both a and d

 

Correct Option: a

 

 

29. Which of the following is strongest?

 

a. microwaves

 

b. IR radiations

 

c. gamma rays

 

d. x-rayss

 

Correct Option: c

 

 

30. The light source in visible spectrophotometer is

 

a. deuterium discharge lamp

 

b. mercury lamp

 

c. tungsten lamp

 

d. hydrogen gas lamp

 

Correct Option: c

 

 

31. Hypochromic effect cause

 

a. decrease in intensity

 

b. shifts to shorter wave length

 

c. and increase in intensity

 

d. none

 

Correct Option: a

 

 

32. Select the groups that produces bathochromic shift when substituted on benzene.

 

a. COOH

 

b. NH2

 

c. CHO

 

d. all

 

Correct Option: d

 

 

33. n to  pi star transition are possible in molecules having electron

 

a. pi bond

 

b. bonding electron

 

c. nonbonding

 

d. sigma bond

 

Correct Option: b

 

 

34. A bonding electron disperses the poly chromatic radiation into band of monochromatic radiations

 

a. chopper

 

b. prism

 

c. both a,b

 

d. grating c

 

Correct Option: c

 

 

35. The polar solvent shift the______ band to longer wave length and the_____band to a shorter wave length

 

a. pi to pi star ,n to n star

 

b. pi to pi*,n to sigma*

 

c. pi to pi*, n to pi*

 

d. n to pi* ,pi to pi*

 

Correct Option: c

 

 

36. Which radiations are also known as inner shell radiations?

 

a. IR

 

b. microwaves

 

c. x-rays

 

d. visible

 

Correct Option: c

 

 

37. Maximum value of absorbance is

 

a. 0 to 2

 

b. 0 to 1

 

c. 0 to 0.5

 

d. all

 

Correct Option: a

 

 

38. Which cell is used in both UV and visible region?

 

a. quartz

 

b. glass

 

c. fused silica

 

d. none

 

Correct Option: a

 

 

39. The base value of a hetroannunular diene is

 

a. 300 nm

 

b. 217 nm

 

c. 253 nm

 

d. 214 nm

 

Correct Option: b

 

 

40. The increment for a single alkyl substituent is

 

a. 15

 

b. 5

 

c. 8

 

d. 10

 

Correct Option: b

 

 

41. Which one of the following is an auxochrome

 

a. C=C

 

b. N=N

 

c. NH2

 

d. c=o

 

Correct Option: c

 

 

42. WHICH SOLVENTS ARE USED IN UV- VISUBLE SPECTROSCOPy

 

a. ethanol c

 

b. n hexane

 

c. water

 

d. all

 

Correct Option: d

 

 

43. Benzene absorbs at

 

a. 204 nm

 

b. 254 nm

 

c. 184nm

 

d. all

 

Correct Option: d

 

 

44. What is the range of normal UV REGION?

 

a. 200 to 380 nm

 

b. 200 to 600 nm

 

c. 200 to 800 nm

 

d. none

 

Correct Option: a

 

 

45. The primary band in aromatic compounds is observed at

 

a. 184nm

 

b. 254nm

 

c. 284nm

 

d. ALL

 

Correct Option: a

 

 

46. Which of the following spectroscopy techniques is associated with molecular emission?

 

a. VISIBLE

 

b. flouresence spectroscopy

 

c. IR

 

d. UV

 

Correct Option: b

 

 

47. The base value for 1,3-pentadiene is

 

a. 100nm

 

b. 217nm

 

c. 224nm

 

d. 80nm

 

Correct Option: b

 

 

48. which one gives better resolution

 

a. grating

 

b. prism

 

c. both have equal

 

d. chooper

 

Correct Option: a

 

 

49. On increasing pH, phenol shows

 

a. BATHOCHROMIC SHIFT

 

b. RED SHIFT

 

c. BOTH

 

d. none

 

Correct Option: a

 

 

50. which one is electronic spectroscopy

 

a. uv-visible

 

b. IR

 

c. NMR

 

d. None

 

Correct Option: a