Chapter 0 Flashcards
aliquot
portion
analyte
substance being measured or detected
aqueous
in water
calibration curve
A graph showing the value of some property versus concentration of analyte. When corresponding property of an unknown is measured, its concentration can be determined from the graph.
composite sample
A representative sample prepared from a heterogeneous material. If the material consists of distinct regions, the composite is made of portions of each region, with relative amounts proportional to the size of each region.
decant
To pour liquid off a solid or, perhaps, a denser liquid. The denser phase is left behind.
heterogeneous
Not uniform throughout.
homgeneous
Having the same composition everywhere.
interference
A phenomenon in which the presence of one substance changes the response in the analysis of another substance.
masking
Process of adding a chemical substance (a masking agent) to a sample to prevent one or more components from interfering in a chemical analysis.
qualitative analysis
Process of determining the identity of the constituents of a substance.
quantitative analysis
Process of measuring how much of a constituent is present in a substance.
quantitative transfer
Transfer of the entire contents from one vessel to another. This process is usually accomplished by rinsing the first vessel several times with fresh liquid and pouring each rinse into the receiving vessel.
random heterogeneous material
A material in which there are differences in composition with no pattern or predictability and on a fine scale. When you collect a portion of the material for analysis, you obtain some of each of the different compositions.
random sample
Bulk sample constructed by takking portion of the entire lot at random.
sample preparation
Transforming a sample into a state that is suitable for analysis. This process can include concentrating a dilute analyte and removing or masking interfering species.
sampling
The process of collecting a representative sample for analysis.
segregated heterogeneous material
A material in which differences in composition are on a large scale. Different regions have obviously different compositions.
slurry
A suspension of a solid in a solvent.
species
Chemists refer to any element, compound, or ion of interest as a species. The word species is both singular and plural.
standard solution
A solution whose composition is known by virtue of the way that it was made from a reagent of known purity or by virtue of its reaction with a known quantity of a standard reagent.
supernatant liquid
Liquid remaining above the solid after a precipitation. Also called supernate.
