ANALYTICAL CHEMISTRY
01 – LABORATORY INTRODUCTION
ANALYTICAL CHEMISTRY
-
Science of obtaining, processing, and
communicating.
Qualitative – descriptive
Quantitative – gives you an idea how much
matter in present (quantity/value)
TERMINOLOGIES
Reaction – change between one or more
chemical elements to form new compound;
chemicals used in a test.
Parts:
Reactant (elements/compounds)
Products (new compounds)
Reversible Reactions – some reactions
which revert.
Reagent – talks about a substance that is used
in reactions; any chemical that gives information
about a reaction.
Precipitate – product of a reaction that is solid.
Produced by mixing two solutions together;
utilized to denote a product of a reaction.
Nickel – Green solution with strawberry red
precipitate (DMG)
Residue – solid produced by separation
methods
or
processes.
Ex.
Filtration,
evaporation, decantation
Filtration – separation of solids from liquids
using a funnel and a filter paper; done when
there is a lot of samples.
Filter Paper
remains.
– collects solid, residue
Filtrate – liquid that goes through filter paper.
Gravity Filtration – filtering through relying
on gravity.
Test Solution – similar to a reagent but with a
specific concentration. When concentration is
specified, it needs to be followed to avoid failure.
Clear Solution – any solution that is not turbid or
cloudy; does not mean colorless. Any solution
wherein light can pass through.
Colorless Solution – one that is not colored.
Test – procedure to show the presence or absence
of some substances.
Positive Test – gives an indication that a
substance is present.
Negative Test – indicates that a substance
is absent
Blank Test – testing without the analyte; to
test for matrix effect (effect of an added
constituent to an analyte); check for validity
or contamination.
Control Test –
Specific Test – test given by one and only
substance.
Ex. Analysis of Nickel
DMG (Dimethyl
answers to nickel.
dioxide)
only
Centrifugation – separates using centrifugal force;
smaller quantities of sample.
Apparatus: Centrifuge
Dense materials (bottom)
YAZMINE EMMANUELLE L HICBAN – BSMT 1C
CHEM102M: LABORATORY
Precipitate – denser than solution; stays on
top.
ANALYTICAL CHEMISTRY APPARATUS
Analytical Balance – used in weighing substances;
very sensitive.
Weighing Boat or Beaker – use to avoid
contamination.
Direct Flame – volatile substance
Water Bath – non volatile
Litmus Paper – test for acids and bases.
Ph Paper – test with quantity.
Precipitation – mixing two reagents in order to
produce a precipitate.
Hydrogen Sulfide (H2S) – gaseous
substance that is a source of sulfide (S2-);
most commonly used precipitating agent.
Used for the following:
a. Group II Cations – precipitated in acidic
environments.
b. Group III Cations – precipitated in basic
environments.
Source:
thioacetamide
(use
precipitation to produce H2S)
indirect
Solid to Liquid Separation – centrifugation and
filtration.
NOTE:
These notes are only discussion notes, and are,
therefore, things that have been said by the professor
during his discussion.
Please refer to the PowerPoint Presentation uploaded
in CeLo+ for additional information.
YAZMINE EMMANUELLE L HICBAN – BSMT 1C