Lecture 5

Question 1

spectrophotometry

Answer 1

• spectroscopy + photometry
• study of interaction of light on a sample
• can tell us what compounds may be present, and in what quantities

Question 2

spectroscopy

Answer 2

study of absorption and emission of radiation (light)

Question 3

photometry

Answer 3

the measurement of intensity of radiation

Question 4

light is made of…

Answer 4

photons

Question 5

higher energy

Answer 5

shorter wavelength (blue)

Question 6

lower energy

Answer 6

longer wavelength (red)

Question 7

electrons in molecules exist in…

Answer 7

orbits/shells

Question 8

photons of the correct wavelength can …

Answer 8

bump up electrons

Question 9

Light energy can…

Answer 9

• generate heat

- produce fluorescence

Question 10

cuvette

Answer 10

tube that holds the sample

Question 11

transmittance

Answer 11

proportion of light that the sample alllows to pass

Question 12

absorbance

Answer 12

the amount of light that sample blocks

Question 13

blank

Answer 13

a comparison sample with none of the measured substance

Question 14

standard curve

Answer 14

a series of known samples used to generate comparison data

Question 15

A (absorabance) =

Answer 15

log(1/T)

Question 16

absorption spectrum

Answer 16

measure a sample at various wavelengths and plot curve of absorbance (useful to determine optimal wavelength for measuring Abs.

Question 17

Beer-Lambert Law

Answer 17

A=elc

Question 18

e

Answer 18

molar absorptivity L/mol cm

Question 19

l

Answer 19

path length in cm (usually constant)

Question 20

c

Answer 20

concentration in mol/L