Lecture 1 - Introduction Flashcards
Deals with the identification and quantification of an analyte in a given sample
analytical chemistry
substance or chemical constituent that is of interest in an analytical procedure
analyte
seeks to establish/confirm the presene of a given element or compound in a sample
qualitative
seeks to establish/confirm the amount of a given element or compound in a sample
quantitative
mass of an analyte or some compound related to it determined
e.g. amount of water lost in a hydrate by heating the sample
gravimetric
volume or mass of a solution which reacts completely with analyte is measured
e.g. acid-base titration and redox reactions
volumetric
the answer should have the same number of decimal places as the term with the fewest decimal places
addition and substraction
the answer should have the same number of significant figures as the term with the fewest significant figures
multiplication and division
the answer should have the same number of significant figures as the term with the fewest significant figures
multiplication and division
is the closeness of a measured value to the true or accepted value
accuracy
describes the agreement among several results obtained in the same way
precision
Absolute error calculation
measured value - true value
Relative error calculation
(measured value - true value/true value) x 100
Relates to reproducibility of results. A precise value need not to be accurate
Precision
Calculations used for precision
- deviation from mean
- mean deviation