INTRO

Question 1

analysts often make use of the special interaction of molecules with ____, with the assistance of analytical instrumentation, such as UV/Vis spectrophotometers, to measure, identify, and even quantify compounds of interest

Answer 1

electromagentic radiation

Question 2

the study of electromagnetic radiation emitted or absorbed by a chemical specie

Answer 2

SPECTROSCOPY

Question 3

the application of spectroscopy so that there are quantifiable results that can be assessed

Answer 3

SPECTROMETRY

Question 4

distance between adjacent peaks or troughs

Answer 4

wavelength

Question 5

the number of wave cycles that travel past a fixed point per unit of time

Answer 5

frequency

Question 6

frequency is represented by a greek letter called

Answer 6

upsilon ν

Question 7

wavelength is represented by a greek letter called

Answer 7

lambda ʎ

Question 8

used to predict what color will be seen when a substance absorbs energy at different specific wavelengths

Answer 8

color wheel

Question 9

composed of broad range of radiation wavelengths in UV, VIS, and IR regions

Answer 9

sunlight (white light)

Question 10

the color of a compound, usually in water or an organic solvent depends on the ____

Answer 10

wavelength of absorbed light

Question 11

change in energy of eelctrons

Answer 11

electronic transition

Question 12

change in distance of atoms in the molecule

Answer 12

vibrational transition

Question 13

change in energy of rotation of molecule around the center

Answer 13

rotational transition

Question 14

absorbance of a substance varies at different wavelengths

Answer 14

Beer-Lambert law

Question 15

A = abc

a = absorptivity
b = path length
c = conc. of analyte

Answer 15

beer-lambert law

Question 16

a characteristic of a substance that is constant at a given wavelength

Answer 16

absorptivity

Question 17

used to measure the different wavelengths that are being absorbed by the analyte, and the magnitude of the absorbance

Answer 17

UV/VIS spectrophotometers

Question 18

• used to hold samples
• can be made of
  * silica or quarts (UV-Vis range)
  * platic or glass (VIS range)

Answer 18

CUVETTES or CELLS

Question 19

CUVETTES OR CELLS

for UV-Vis range

Answer 19

silica or quartz

Question 20

CUVETTES OR CELLS

for VIS range

Answer 20

plastic or glass

Question 21

• measures the absorbance of specific colors
• limited to visible range of wavelengths

Answer 21

COLORIMETER

Question 22

• measures transmittance as a function of wavelength
• can measure wavelengths of UV, VIS, and IR regions

Answer 22

SPECTROPHOTOMETER

Question 23

PARTS OF A SPECTROPHOTOMETER

lens

Answer 23

collimator

Question 24

PARTS OF A SPECTROPHOTOMETER

slit

Answer 24

wavelength selector

Question 25

# **PARTS OF A SPECTROPHOTOMETER** photocell

Answer 25

detector

Question 26

# **PARTS OF A SPECTROPHOTOMETER** emits **high**, constant amount of **energy**

Answer 26

light source

Question 27

# **PARTS OF A SPECTROPHOTOMETER** **separates** light into discreet wavelengths

Answer 27

monochromator | **prism or grating**

Question 28

# **PARTS OF A SPECTROPHOTOMETER** sample holder

Answer 28

cuvette

Question 29

# **PARTS OF A SPECTROPHOTOMETER** light detector

Answer 29

digital display or meter

Question 30

wavelengths used are between **190-800nm**

Answer 30

UV/Vis analysis

Question 31

wavelengths used are between **1000-15000nm**

Answer 31

IR analysis

Question 32

region **most widely used** for **qualitative** analysis

Answer 32

NEAR IR

Question 33

* expressed in **micrometer** and **wavenumber** * involves **molecular vibrations** * wavenumber = **1/wavelength x 10⁴**

Answer 33

IR analysis

Question 34

movement of atoms **back and forth** along the bond axis

Answer 34

stretching

Question 35

change in **bond angles** between two atoms that are each attached to a third

Answer 35

bending

Question 36

# **BASIC IR INSTRUMENT DESIGN** **zirconium** & **yttrium** oxides

Answer 36

Nernst glower

Question 37

# **BASIC IR INSTRUMENT DESIGN** silicon carbide

Answer 37

globar

Question 38

# **BASIC IR INSTRUMENT DESIGN** **merges** two or more **sources of light** to create an **interference pattern**

Answer 38

INTERFEROMETER

Question 39

# **FOURIER TRANSFORM INFRARED (FTIR) SPECTROMETERS** located **after** the **IR source** and **before** the **beam splitting**

Answer 39

INTERFEROMETER

Question 40

# **FOURIER TRANSFORM INFRARED (FTIR) SPECTROMETERS** **IR spectrum** is scanned ____ using a **moving mirror system**

Answer 40

very quickly

Question 41

uses **molecular assignments** for the IR spectra

Answer 41

FOURIER TRANSFORM INFRARED (FTIR) SPECTROMETERS

Question 42

Can be used to: * **assign structures** to both known compounds * **elucidate** the structure * identity of an **unknown** compound or sample

Answer 42

**FOURIER TRANSFORM INFRARED (FTIR) SPECTROMETERS**