Spectrophotometer

Question 1

measurement of light intensity in a much
narrower wavelength.

Answer 1

Spectrophotometry

Question 2

It uses a device
(prisms and/or gratings) to disperse the
source of light into a continuous spectrum.

Answer 2

Spectrophotometry

Question 3

2 Dispersing element or monochromator

Answer 3

prism (triangle) and grating

Question 4

Basic component device

Answer 4

Light source
Entrance slit
Dispersive elements
Exit slit
Sample
Detector

Question 5

Basic
Components

Answer 5

Light source
Device to isolate light of a desired wavelength
Cuvet
Photodetector
Read-out device
Data system

Question 6

Different light sources

Answer 6

Continuum source

Line source

Question 7

emits radiation that changes in
intensity/ Immites radiation wide source

Answer 7

Continuum source

Question 8

type of light Source

Answer 8

Tungsten iodine lamp
Quartz halide lamp
Deuterium discharge lamp
Infrared energy source

Question 9

Most commonly used light source

Answer 9

Tungsten iodine lamp

Question 10

contains small amounts of
halogen such as iodine to prevent the decomposition
of the vaporized tungsten from the very hot filament.

Answer 10

Quartz halide lamp

Question 11

provides energy source
with high output in the UV range (down to 165 nm).

Answer 11

Deuterium discharge lamp

Question 12

used above 800 nm.

Answer 12

Infrared energy lamp

Question 13

It is a device more sophisticated it isolates the narrow band of wavelengths from visible and ultraviolet sources

Answer 13

Monochromator

Question 14

monochromator is made up of three parts:

Answer 14

Entrance slit
Dispersive elements
Exit slit

Question 15

is a small circular or rectangular hole cut in an otherwise opaque plate,
such as a black metal plate.

Answer 15

Slit

Question 16

is where light enters the monochromator from the source. Its
purpose is to create a unidirectional beam of light of appropriate intensity
from the multidirectional light emanating from the source

Answer 16

Entrance Slit

Question 17

After passing through the entrance slit, the beam
encounters a ______________

Answer 17

Disperse element

Question 18

The narrow band of the spectrum is then selected by the ______________

Answer 18

Exit slit

Question 19

is rotated, the spray of colors moves
across the exit slit such that a different narrow wavelength range
emerges from the exit slit at each position of rotation.

Answer 19

Disperse element

Question 20

is a three-dimensional triangularly shaped glass or quartz
block. When the light beam strikes one of the three faces of the
prism, the light emerging through another face is dispersed.

Answer 20

Prism

Question 21

is like a highly polished mirror that has a large
number of precisely parallel lines or grooves scribed onto its
surface. Light striking this surface is reflected, diffracted, and
dispersed into the component wavelengths-

Answer 21

Diffraction grating

Question 22

Type of Detectors:

Answer 22

Photomultiplier and photodiodes

Question 23

are
used as detectors in UV-VIS
spectrophotometers

Answer 23

Photomultiplier tubes or
photodiodes (light sensors)

Question 24

is a light sensor combined with
a signal amplifier. The light emerging from the sample
compartment strikes the photosensitive surface and
the resulting electrical signal is amplified.

Answer 24

Photomultiplier

Question 25

The photomultiplier tube consists of a

Answer 25

Photocathode, anode, and dynodes

Question 26

This amplified signal is then sent on to the
readout

Answer 26

Photomultiplier

Question 27

Photodiodes Utilizes materials such as

Answer 27

Silicon

Question 28

Silicon can be doped with impurities to make it either electron rich

Answer 28

BORAN n- type semiconductor

Question 29

electron poor

Answer 29

p-type semiconductor

Question 30

used for UV-VIS spectrophotometry must be transparent to all wavelengths of
light for which it is use

Answer 30

Cuvette

Question 31

If visible light is used, the material must ideally be completely clear and colorless, which
means that inexpensive materials, such as

Answer 31

Colorless glass or plastic

Question 32

For visible light spectrophotometry, the cuvettes must be made of

Answer 32

Colorless glass or plastic

Question 33

For ultraviolet spectrophotometry, the cuvettes must be made of

Answer 33

Quartz

Question 34

Warm
Up spectrophotometry

Answer 34

20 mins

Question 35

is a contaminating
substance that gives an absorbance
signal at the same wavelength or
wavelength range selected for the
analyte.

Answer 35

Interference

Question 36

• can be high or low because of it

Answer 36

Interference