UV Visible Spectroscopy Interview Questions and Answers

1 Solvatochromism is the ability of a substance to change colour due to

A A change in wavelength of the incident radiation

B A change in the solvent viscosity

C A change in molecular weight of the substance

D A change in the solvent polarity

Answer:A change in the solvent polarity

2 Two compounds A and B have molar absorptivity as 1200 and 15,000 mol lit ^-1cm ^-1 respectively. Which of the following statements is correct regarding them?

A Compound A can be detected at very low concentrations than compound B.

B Compound B can be detected at very low concentrations than compound A.

C Both compounds can be detected at very dilute concentrations.

D Molar absorptivity have no influence on the detection of compounds.

View Answer

Answer:Compound B can be detected at very low concentrations than compound A.

3 Which of the following shows bathochromic shift in polar solvent

A Water

B Ethanol

C Ethylene

D Chloroform

View Answer

Answer:Ethylene

4 The colour of a substance perceived by human eye is

A Same as that the substance emits in flame

B Same as that the substance absorbs

C Not same as that the substance absorbs

D Not same as that the substance emits

View Answer

Answer:Not same as that the substance absorbs

5 The color of potassium permanganate solution is due to

A n→π *

B π→π *

C d →d*

D n→s*

View Answer

Answer:d →d*

6 Which of the following detector has fast response time

A Photomultiplier tube

B Photo tube

C photo diode array

D Barrier layer cell

View Answer

Answer:photo diode array

7 The light which reaches the detector without passing through the cell is known as

A Dark radiation

B Stray radiation

C Photoluminescence

D Chemiluminescence

View Answer

Answer:Stray radiation

8 A sample exhibited has an absorbance 1.0 in UV-Visble spectroscopy. the percentage transmittance will be

A 1%n

B 0.1%

C 10%

D 0.01%

View Answer

Answer:10%

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

A Photocathode

B Photoanode

C Metal junction

D Metal layer

View Answer

Answer:Photocathode

10 The absorptivity of a standard sample of 1% w/v solution measured at a path length of 1 cm, A(1%, 1 cm), is 312 at 254 nm. The absorbance of the test sample was observed 0.624 at 254 nm. The concentration of test sample is

A 5 g/100ml

B 5 mg/100 ml

C 2 g/100ml

D 2mg/100 ml

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