Chapter 1 Flashcards
abscissa
The x-axis of a graph.
anhydrous
Adjective describing a substance from which all water has been removed.
atomic mass
Number of grams of an element containing Avogadro’s number of atoms.
back titration
One in which an excess of standard reagent is added to react with analyte. Then the excess reagent is titrated with a second reagent or with a standard solution of analyte.
blank titration
One in which a solution containing all reagents except analyte is titrated. The volume of titrant needed in the blank titration should be subtracted from the volume needed to titrate the unknown.
concentration
An expression of the quantity per unit volume or unit mass of a substance. Common measures of concentration are molarity (mol/L) and molality (mol/kg of solvent).
density
Mass per unit volume.
direct titration
One in which the analyte is treated with titrant and the volume of titrant required fro complete reaction is measured.
electrolyte
A substance that produces ions when dissolved.
end point
Point in a titration at which there is a sudden change in a physical property, such as indicator color, pH, conductivity, or absorbance. Used as a measure of the equivalence point.
equivalence point
Point in a titration at which the quantity of titrant is exactly sufficient for stoichiometric reaction with the analyte.
formal concentration
F, the molarity of a substance if it did not change its chemical form on being dissolved. It
formula mass
FM, The mass containing one mole of the indicated chemical formula of a substance.
gravimetric analysis
Any analytical method that relies on measuring the mass of a substance (such as a precipitate) to complete the analysis.
gravimetric titration
A titration in which the mass of titrant is measured, instead of the volume. Titrant concentration is conveniently expressed as mol reagent/kg titrant solution. Gravimetric titrations can be more accurate and precise than volumetric titrations.
indicator
A compound having a physical property (usually color) that changes abruptly near the equivalence point of a chemical reaction.
liter
The volume of a cube that is 10 cm on each edge.
molality
m, A measure of concentration equal to the number of oles of solute per kg of solvent.
molarity
M, A measure of concentration equal to the number of moles of solute per liter of solution.
mole
mol, SI unit for the amount of substance that contains as many molecules as there are atoms in 12 g of (12)^C. There are approximately 6.022 x 10^(23) molecules per mole.
molecular mass
The number of grams of a substance that contains Avogadro’s number of molecules.
ordinate
The y-axis of a graph.
parts per billion
ppb, An expression of concentration denoting nanograms of solute per gram of solution
parts per million
An expression of concentration denoting micrograms of solute per gram of solution.
primary standard
A reagent that is pure enough and stable enough to be used directly after weighing. The entire mass is considered to be pure reagent.
product
The species created in a chemical reaction.
reactant
The species consumed in a chemical reaction.
reagent grade chemical
A high-purity chemical generally suitable for use in quantitative analysis and meeting purity requirements set by organizations such as the ACS
SI units
International system of units based on the meter, kilogram, second, ampere, kelvin, candela, mole, radian, and steradian.
solute
A minor component of a solution.
solvent
Major constituent of a mixture.
standardization
Process of determining the concentration of a reagent by reaction with a known quantity of a second reagent.
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.
stoichiometry
Ratios of substances participating in a chemical reaction.
titrant
Substance added to the analyte in titration.
titration
A procedure in which one substance (titrant) is carefully added to another (analyte) until complete reaction has occurred. The quantity of titrant required for complete reaction tells how much analyte is present.
titration error
Difference between the observed endpoint and the true equivalence point.
trace analysis
Chemical analysis of very low levels of analyte, typically ppm and lower.
volume percent
Defined as (volume of solute/volume of solution) x 100.
volumetric analysis
A technique in which the volume of material needed to react with the analyte is measured.
weight percent
(Mass of solute/mass of solution) x 100
