mass
amount
molar mass
concentration
solution volume
gas volume
molar gas volume
Avogadro
constant, L
number of
entities, N
P3. ACID-BASE NEUTRALIZATION REACTIONS
P3.2 Defining Acids & Bases
Appropriate definitions depend on the level of study and also the chemical system being considered.
GCSE
ACID - a substance which dissolves in water forming a solution containing hydrogen ions that may be replaced by a metal to form a salt.
BASE - a substance which can neutralize an acid, epitomised by metal oxides, hydroxides and carbonates.
iGCSE - while the above certainly holds true, the formal definition below might be demanded.
In aqueous solution an acid is a proton donor while a base is a proton acceptor.
Requirements for IB-SL & HL, 'A' level, AP & pre-U will require the definition above in terms of the Brønsted & Lowry theory of acidity, identifying acid-base conjugates also. However, additional emphasis may be required in terms of the Lewis definition of acids & bases, particularly when moving away from aqueous solution and protic solvents.
The URL links above should provide sufficient detail for most pre-university courses in chemistry or physical science.
P3.3 Dilute & Concentrated Acids
DILUTE ACIDS
Usually have a concentration of 2 mol/L (2 M) or less. They contain a small proportion of substrate acid compared to solvent molecules. The 'bench' strength of an acid is usually 2 M.
CONCENTRATED ACIDS
Are almost pure acids with a very small percentage of water (but note HCl). They can be very corrosive. The concentration of a given pure acid varies depending on its nature.
Data for three common mineral acids and acetic acid in their concentrated forms are tabulated below.
