Quantitative Analysis Ch. 18
Single beam spectrophotometer process
Only look at top half of image. light source --> monochromator --> sample --> light detector.
Transmittance equation
P = original light Po = sample
What are light particles called?
Photon
Which waves have wavelengths between 10nm and 400nm?
Ultraviolet waves
Which waves can be seen by the naked eye?
Visible waves
What does the lambda (λ) symbol mean.
Wavelength
Spectrophotometric titration definition
Which absorption or emission of light is used to monitor the progress of the titration reaction and to find the equivalence point.
Which waves can be created by colliding high velocity electrons with a metal plate?
X-ray waves
Positive deviation from Beer's law
chemical effects
Negative deviations from Beer's law
chemical effects polychromatic light Stray light
Absorbance is so important because it is _____ proportional to the concentration
directly
atomic absorption experimental schematic
draw and label
blackbody radiation
emission of light from hot objects
Definition of a molecule in an excited state.
Any state of an atom or a molecule having more than the minimum possible energy.
What does (c) mean in the Relation between frequency and wavelength formula?
(C) is the speed of light
Corrected absorbance formula
(total volume / initial volume) (observed absorbance)
When light is absorbed by a sample, the irradiance of the beam of light is _____.
Decreased
components of the hollow-cathode lamp
Draw and label
luminescence experimental setup
Draw the boxes and label
Energy is proportional to frequency equation
E = (hc/λ) = hc (1/λ)
Relationship between energy and a photon equation
E = hu u: photon
Beer's Law definition
explains the relationship between absorbance, at a given wavelength and concentration
Irradiance (P)
is the energy per second per unit area of the light beam
It is convenient to describe light in terms of both _____ and ____.
particles and waves.
Which waves have the longest wavelength?
radio waves
If a molecule emits a photon, the energy of the molecule is _____.
Lowered.
Which waves have frequencies between 300MHz and 300GHz?
Microwaves
Hertz definition
One oscillation per second
True/False energy is proportional to frequency.
True
How many Hertz are in one frequency?
1 Hz = 1 frequency
What is the number for the speed of light (c)?
2.998 * 10^8 m/s
What is the number for Planck's constant?
6.626 * 10^-34 J*s
luminescence definition
Emission of light from an excited state of a molecule.
Each photon carries what?
Energy (E).
Relation between energy and frequency formula.
Energy = (Planck's constant)(frequency)
What does the nu (ν) symbol mean.
Frequency
Which waves have the highest frequency?
Gamma ray waves
high frequency --> high energy is what?
Gamma rays
What natural effect is an example of blackbody radiation
Green House effect
When a molecule absorbs a photon, the energy of the molecule ____.
Increases
Which waves are used for night vision?
Infrared waves
Low frequency --> low energy is what?
Radio waves
Definition of a molecule in a ground state.
State of an atom or a molecule with the minimum possible energy.
Absorbance definition
The amount of light absorbed by a sample
chromophore definition
The part of a molecule responsible for light absorption
Transmittance (T)
The passing of light through a sample
What does (1/λ) mean?
This is a wavelength number and it is the reciprocal of the wavelength.
The relation between frequency and wavelength is is done by what formula?
speed of light = (wavelength)(frequency)
Equation that shows the energy it takes for a molecule to go from ground state to excited state.
ΔE = E1 - Eo ΔE: difference in energy between two states E1: excited state Eo: ground state
