FINAL Flashcards
(15 cards)
what are the three types of error?
random (noise), gross (human), systematic (bias)
why is a calibration curve or standard curve necessary in chemical analysis?
to measure the detector response for different analyte concentrations
A representative sample from a segregated heterogeneous material requires
the number of samples taken from each region of the material to be proportional to the relative size of this region
Molar absorptivity varies with
wavelength
UV-Vis spectroscopy looks at
outershell electron transitions
Most to least energy for photons:
gamma rays, X-rays, ultraviolet radiation, visible light, infrared radiation, and radio waves
what is NOT a way to decrease absorbance at a certain wavelength
decreasing the molar absorptivity
What is the relationship between the concentration of analyte and cell voltage of an ion selective electrode
the concentration of analyte is proportional to the log of the voltage in the cell
Why is a three electrode potentiostat used?
to eliminate the voltage measurement error that can occur at high currents
measurement with an ion selective electrode is an example of
potentiometry
What are the 8 Beer Law assumptions
-Monochromatic Light (single wavelength)
-Parallel light
-Solution concentration not too high (or low)
-Uniform sample distribution
-Uniform sample path
-No Reflection
-No stray light
-No fluorescence
In which type of chromatography is the interaction between analyte and stationary phase due to molecule size ONLY?
gel permeation chromatography
Which type of chromatography uses liquid as a stationary phase
partition chromatography
What is the visible light spectrum, and which extreme is which?
400-800 nm (400 is purple and 800 is red)
PPM conversion if density = 1
1 mg/L
