mass
amount
molar mass
concentration
solution volume
gas volume
molar gas volume
Avogadro
constant, L
number of
entities, N
CALCULATING ON THE SIDE OF SUCCESS – Support Module P: NAVIGATING CHEMICAL REACTIONS
P. NAVIGATING CHEMICAL REACTIONS
P1. CLASSIFYING INORGANIC CHEMICAL REACTIONS
Introduction
Despite the vast number of different inorganic chemical reactions known to occur, it is possible to classify them using only FOUR categories:
The phlogiston theory was the basis for research in chemistry for much of the c.18th. In 1772, however, Antoine Lavoisier noted that non-metals gain significant mass when burned in air, e.g., the mass of phosphorus increases by about 2.3x. To account for this large mass change, Lavoisier concluded that phosphorus must combine with something in air when it burns, this being corroborated by the observation that the volume of air decreases by a factor of 20 % when phosphorus combusts in a limited amount of air.
Lavoisier suggested the name oxygene (‘acid-former’) for the substance absorbed from air when a material burns since the products of the combustion of non-metals such as phosphorus
Historically, the first step towards a classification of chemical reactions was taken by
Georg Ernst Stahl in 1697 when he proposed the phlogiston theory, which was based on
observations made when heating metals in air and also heating the products of such reactions with charcoal.
form acidic solutions once dissolved in water.
- aqueous phosphoric acid