1st Exam Definitions Flashcards
Deals with the identification of compounds present in a sample
Qualitative
Concerned with determination of amount
Quantitative
Considers amounts to diagnose or check certain compounds in various fields
Analytical chemistry
Classification of quantitative methods of analysis (3)
Gravimetric method
mass of compound
Volumetric method
Volume of a solution and reaction
Instrumental method
Employs instruments
Types of instrumental method (3)
Electroanalytical
|Measures electrical properties such as potential, current, resistance, quantity of electricity
—–potentiometry, coltammetry
Spectroscopic
Interactions between electromagnetic radiation and atoms
—— spectroscopy
Chromatographic
——-Separation of sample components based on migration rates
——-Thin layer chromatography
Extent of Analyses (3)
complete or exact
-each constituent amount is determined
Ultimate analysis
Each element is determined
Proximate or partial analysis
Selected constituent only determined
Types of size sample
macro >100 mg
semimicro 10-100 mg
micro 1 - 10 mg
ultramicro <1 mg
Types of solutions (2)
Standard Solutions
precisely know concentration
Stock Solutions
Very high concentration, stable, used to store
Flow chart (11)
Select method
Acquire Sample
Process Sample
Is sample soluble Carry out chemical dissolution
Change chemical Form Measurable property?
Eliminate Interferences
Measure Property XX
Calculate Results
Estimate Reliability of Results
Describes the reproducibility of the measurements:
Telss how close the results are.
standard deviation
Variance
Coefficient of variation
Precision
Indicates the closeness of the measurements to its true value
absolute error
relative error
Accuracy
Types of Errors (3)
Random / Indeterminate Error
Data scattered around a mean value, precision
Systematic / Determinate Error
mean differ from accepted value
Gross Error
large mistakes that lead to outliers
Sources of Systematic Errors
Instrumental error
Methodic error
Personal error
