Analytical Chemistry Terms

CHMB16

qualitative

what is it? (finding the chemical identity and properties of what’s being tested)

qualitative methods

NMR spectroscopy

UV spectroscopy (more quantitative)

IR spectroscopy (more qualitative)

quantitative

how much of it? (a numerical value)

quantitative methods

Titration

NMR spectroscopy

UV spectroscopy (more quantitative)

IR spectroscopy (more qualitative)

Sampling

collecting and testing a small amount of something that is able to represent the population

heterogeneous

when you can see the difference in the components of the solution (may need to use microscope sometimes)

homogeneous

when you can’t see the difference in the components of the solution

separation methods to eliminate interferents

distillation / BP

filtration

precipitation

crystallization

chromatography

centrifuging

liquid-liquid extraction

solvent extraction

feedback system

continuous measurement and control

feedback loop

continuous measurement, COMPARISON and control. (constantly adjusting procedure to improve accuracy and precision)

weight

F=mg (sensitive to altitude)

mass

found by weighing by difference

mol

SI unit for how much of a chemical substance

Avogadro’s #

6.022 × 10²3

molar mass

mass of a substance in 1 mol

express conc.

1. mole conc.

a. molarity (M)

b. molality (m)

2. % conc.

a. weight %

b. V %

weight / V %

molarity (M)

mol solute / L solution

molality (m)

mol solute / kg solvent

% conc.

1. weight %

2. volume %

3. weight / volume %

weight % (w/w)

weight solute / weight solution

volume %

V solute / V solution

weight / volume %

weight solute / V solution

formal conc.

how a solution was made (even if substance used turned into another species)

ex. 0.44M of MgCl2 IS WRONG because that’s how you made it, not for sure what is dissolved.

conc. in ppm and ppb

c(ppm) = (mass of substance / mass of sample) x 10^6

c(ppb) = (mass of substance / mass of sample) x 10^9

ppm (aq. solution) = 1 mg / L

ppb (aq. solution) = 1 μg / L