Final Terms

Analytical Balance
An analytical balance measures masses to within 0.0001 gram; used when precise measurement is needed
Top-loading balance
Used to weigh solid material when a precision of 0.1 gram
Systematic Error
also called determinate error; error due to procedural or instrumental factors that cause a measurement to be consistently too large or too small
Confidence Interval
the range of values within which there is a specified probability that the true value will be found
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.
Titration Error
The difference between the observed end point and the true equivalence point in a titration
a compound having a physical property (usually color) that changes abruptly near the equivalence point of a chemical reaction
Indicator Error
The difference between the indicator end point of a titration and the true equivalence point
Kjeldahl Nitrogen
Nitrogen in organic compounds; compound is digested with boiling H2SO4 to convert nitrogen to NH4+, which is treated with base and distilled as NH3 into a standard acid solution. Moles of acid consumed = moles of NH3 liberated
a single multidentate ligand that forms metal complexes that are more stable than those formed by several individual ligands with the same ligand atoms
Complexometric Titration
A titration in which the reaction between analyte and titrant involves complex formation
Direct Titration
A titration in which the analyte is treated with titrant, and the volume of titrant required for complete reaction is measured
Displacement Titration
An EDTA titration produced in which analyte is treated with excess MgEDTA2- to displace Mg2+. The liberated Mg2+ is then titrated with EDTA; useful if no suitable indicator for direct titration of M^n+
Indirect Titration
A titration that is used when the analyte cannot be directly titrated. For example, analyte A may be precipitated with excess reagent R. The product is filtered, and the excess R washed away. Then AR is dissolved in a new solution, and R can be titrated.
Formation Constant
The equilibrium constant for the reaction of a metal with its ligands to form a metal-ligand complex; same as stability constant
Lewis Acid
one that can form a chemical bond by sharing a pair of electron donated by another species
Lewis Base
one that can form a chemical bond by sharing a pair of its electron with another species
an atom or a group attached to a central atom in a molecule. The term is often used to mean any group attached to anything else of interest.
Masking Agent
A reagent that selectively reacts with one (or more) component(s) of a solution to prevent the component(s) from interfering in a chemical analysis
Monodentate Ligand
one that binds to a metal ion through only one atom
Multidentate Ligand
one that binds to a metal ion through more than one atom
Adsorption Indicator
used for precipitation titrations, it becomes attached to a precipitate and changes color when the surface charge of the precipitate changes sign at the equivalence point
Argentometric Titration
one using only Ag+ ion
Fajans Titration
a precipitation titration in which the end point is signaled by adsorption of a colored indicator on the precipitate
Mohr titration
Titration with silver nitrate to determine the concentration of chlorides in a solution
Volhard Titration
titration of Ag+ with SCN- in the presence of Fe3+. Formation of red Fe(SCN)2+ marks the end point
the electrode at which oxidation takes place
the electrode at which reduction takes place
Galvanic/Voltaic Cell
one that produces electricity by means of a spontaneous chemical reaction
the use of triiodide (or iodine) as a titrant
a technique in which an oxidant is titrated with I- to produce I3-, which is then titrated (usually with thiosulfate)
same as oxidizing agent; a substance that takes electrons in a chemical reaction
a loss of electrons or a raising of the oxidation state
Redox Reaction
a chemical reaction in which electrons are transferred from one element to another
Reducing Agent
same as reductant; a substance that donates electrons in a chemical reaction
a gain of electrons or a lowering of oxidation state