CC LEC - Instrumentation

Question 1

principle of spectrophotometry

Answer 1

measures array of lights or radiant energy absorbed or transmitted

Question 2

state beer’s law

Answer 2

Concentration of substance directly proportional to amount of light absorbed or logarithm of transmittedlight

Question 3

component of spectro

source of light energy

Answer 3

exciter lamp

Question 4

examples of light source

Answer 4

tungsten, halogen, vapor, mercury, xenon lamps

Question 5

controls amount of light that enters monochrom

Answer 5

entrance slit

Question 6

produces light of specific wavelength from exciter lamp

Answer 6

monochromator

Question 7

types of monochromator

Answer 7

prism
diffraction gratings
interference fitlers

Question 8

holds sample to be analyzed

Answer 8

cuvette or analytical cell

Question 9

type of cuvette for acidic solution

Answer 9

soft glass

Question 10

type of cuvette for alkaline solution

Answer 10

borosilicate

Question 11

three types of cuvette

Answer 11

soft glass
borosilicate
quartz or plastics

Question 12

detects and collects light energy transmitted

converts it into a current to produce a readable output

Answer 12

photodetector

Question 13

types of photodetectors (4)

Answer 13

barrier layer cells
phototube
photomultiplier tubes
semiconductor

Question 14

be used to protect cuvette from unwanted light that may cause measurement errors

Answer 14

light shield

Question 15

preferably used in spectrophotometer because they reduce incident light

Answer 15

rectangular cuvette

Question 16

use to check wavelength calibration of spectrophotometer

Answer 16

holmium oxide or didymium filters

Question 17

filters or solutions with sharp cut off wavelength for transmission

Answer 17

nickel II sulfate

Question 18

type of spectrophotometer

absorbance is measured at 2 different wavelengths using light from either single or 2 monochrom

Answer 18

double-beam