Analytical Chemistry Lecture Flashcards

Vocabulary practice flashcards covering fundamental terminology, analytical methods, titration types, and stoichiometry in analytical chemistry.

Analytical Chemistry

The branch of chemistry concerned with finding out the identities and quantities of the different chemical components which a substance contains.

Chemical Analysis

Any chemical process that is used to measure or identify the components of a sample.

Qualitative Analysis

A type of chemical analysis that identifies which components are present in a sample.

Quantitative Analysis

A type of chemical analysis that measures the proportions of each component present in a sample.

Component

A chemical compound, ion, or element; all components together form the material being analysed.

Sample

A smaller representative part of the material to be analysed that contains every component in the same proportions as the original material.

Analyte

The particular component in a sample to be identified or measured.

Interference

Any process or component that causes the wrong answer from chemical analysis to be obtained.

Gravimetric Analysis

A method of chemical analysis based on measuring the mass of (a compound of) the analyte.

Titrimetric Analysis

A method of chemical analysis (also known as volumetric analysis) based on measuring the quantity of a reagent that reacts with the analyte.

Spectroscopic Analysis

A method of chemical analysis based on measuring the intensity of electromagnetic radiation absorbed or emitted by the analyte.

Electrochemical Analysis

A method of chemical analysis based on measuring the current, voltage, or conductivity due to the presence of analyte.

Radiochemical Analysis

A method of chemical analysis based on measuring the nuclear radiation (number of radioactive particles) emitted by the analyte.

Accuracy

The closeness of a measurement to the "true" result.

Precision

The closeness of a series of measurements to each other.

Titrant

The reagent solution of known concentration, typically placed in the burette during a titration.

Titrand

The analyte solution of unknown concentration, typically placed in the flask during a titration.

Equivalence Point

The point in a titration where exactly the right volume of titrant has been added to react with all the titrand present in the sample.

End Point

The point in a titration where the indicator changes colour.

Primary Reagent Indication

A method of locating the equivalence point where a reactant or product directly indicates reaction completion via a colour change without an added indicator.

Ancillary Reagent Indication

A method of locating the equivalence point using an added indicator dye that reacts with titrand or titrant to produce a colour change.

Standardisation

The procedure performed immediately before analysis to measure the exact concentration of a titrant using a primary standard.

Primary Standard

A pure, dry, readily available solid of known composition that forms a stable solution over time and reacts predictably with a titrant.

$$\text{pH}$$

A logarithmic measure of acidity defined as $\text{pH} = -\log_{10}[H^+]$, where $[H^+]$ is the hydrogen ion concentration in $mol\,dm^{-3}$.

Complex

A chemical compound containing a central metal atom or ion surrounded by ligands arranged in a defined geometric formation.

Ligand

A molecule or ion bound to a central metal centre in a complex.

EDTA

Ethylene Diamine Tetraacetic Acid; a tetra-basic acid titrant used in complexometric titrations to form stable anionic complexes with metal cations.

Concentration ($C$)

The mass of a substance per unit volume, expressed in $g\,dm^{-3}$ and calculated as $C = \frac{\text{mass}}{V}$.

Molarity ($M$)

Molar concentration, defined as the number of moles ($n$) of a substance per unit volume ($V$) in $dm^3$, expressed in $mol\,dm^{-3}$.

Stoichiometry

The ratio of the number of moles of reactants and products involved in a balanced chemical reaction.

Oxidation

The loss of electrons by a chemical species during a reaction.

Reduction

The gain of electrons by a chemical species during a reaction.

Oxidant

A chemical species (oxidizing agent) that removes electrons from a reductant and is itself reduced.

Reductant

A chemical species (reducing agent) that gives up electrons to an oxidant and is itself oxidised.

Complementary Reagents

Reagents used together in analysis, such as iodine ($I_2$) and sodium thiosulfate ($Na_2S_2O_3$) in iodine titrations.