QC 2 L1.2 Flashcards
measurement of light
PHOTOMETRY
most commonly used measurement in the laboratory because
light can undergo
PHOTOMETRY
Spectrophotometry
Absorption
Nephelometry
Scatter
Turbidimetry
Reflection
Flame Spectroscopy
Emission
Fluorometry
Fluorescence
it is a function of its wavelength
color of light
is a form of electromagnetic energy that appears to
travel in waves
Light
law stating that the power of a transmitted radiant beam
decreases exponentially as the concentration of the solution
containing the absorbing chemical species increases
arithmetically
BEER’S LAW
What is the relationship between Transmittance = Concentration
inversely proportional
What is the relationship between Transmittance = Thickness
inversely proportional
What is the relationship between Absorbance = Thickness
Directly Proportional
What is the relationship between Absorbance = concentration
Directly Proportional
What is the relationship between number of solute = concentration
Directly Proportional
used to represent the logarithm of transmittance
ABSORBANCE
increases linearly with concentration
ABSORBANCE
also known as “optical activity”, “absorbancy” or
“extinction coefficient”
ABSORBANCE
relationship of absorbance to concentration
Beer’s Equation
What is the formula for Beer’s Equation
A = a b C
where,
o A = absorbance
o a = absorptivity coefficient (constant)
o b = length of light path (constant)
o C = concentration
the absorbance of an
unknown concentration (u) of a particular constituent is
compared with the absorbance of a known concentration (s)
spectrophotometric analysis
states that the power of a transmitted radiant beam decreases exponentially as the thickness of the solution containing the absorbing chemical species increases
arithmetically
LAMBERT’S OR BOUGUER’S LAW
combination of the above laws and relates the power of the
incident beam and transmitted beam to the thickness and
concentration of the solution containing the absorbing
chemical species
BEER-LAMBERT’S / BEER-BOUGUER’S LAW
True or false
↓ conc. solute = ↓ light abs = ↓ transmitted light
False
↓ conc. solute = ↓ light abs = ↑ transmitted light
True or false
↑ conc. solute = ↑ light abs = ↓ transmitted light
True
What is the relationship between wavelength = emitted energy
inversely proportional
