Ch 0 and 1 Flashcards
analytical chemistry
the chemicals characterization of matter
factors of analytical characterization
quantitative, qualitative
qualitative analysis
what type of ions or compounds discovered in a sample
quantitative
how much of a known substance present in a sample
the analytical process
defining the problem, select the analytical procedure, sampling, sample preparation, analysis, report results, drawing conclusions
defining the problem
analyze- substance being measured on analyzed
select the analytic procedure
depends on sample type
sampling
obtain a representative sample
homogenous
composition is the same everywhere
ex. chocolate
heterogeneous
composition differs from place to place
ex. macadamia nuts in chocolate
sample preparation
convert sample into a form suitable for analysis by the selected method
ex. removing fat from chocolate because it interferes with chromatography
analysis
measure the concentration of analyte (substance being measured) in several different aliquots (portions)
-basically saying that you measure the concentration of the substance act different points in time
replicate measurements
to generate variability or uncertainty in analysis
uncertainty leads to more what?
accuracy
report results
present clearly written report with results and any limitation to the analysis
limitations
accuracy or precise of data
avogadro’s number
6.022 x 1023
millimole
mg/MW
concentrations of solutions
amount of solute in a given amount of material
molarity (M)
of moles per liter of solution (total solution)
formal concentration (F)
molarity of a strong electrolyte
molality (m)
of moles of a substance per kilogram of solvent
what is the relationship between temp and molarity?
the relationship is indirectly proportional; the temp is increased molarity is decreased
why: temp is increased, solution volume expands so the concentration is lowered
density
g/cm3=g/mL
