8.1 Theories of acids and bases

8.1.1 Define acids and bases according to the BrØnsted-Lowry and Lewis theories
BrØnsted - Lowry acid              H+/proton donor
BrØnsted - Lowry base              H+/ proton acceptor
Lewis acid                                 electron pair acceptor (dative bond)
Lewis base                                 electron pair donor (dative bond)

8.1.2 Deduce whether or not a species could act as a BrØnsted-Lowry and/or a Lewis acid or base.

All BrØnsted-Lowry acids are Lewis acids, but not all Lewis acids are BrØnsted-Lowry acids.

Some species can act as acids/bases (amphoteric/ amphiprotic substances)
Amphoteric:
- B-L acid must be able to disscociate + release H+
- B-L base must be able to accept H+, therefore must have a lone electron pair
According to B-L theory they must possess both a lone e- pair and hydrogen that can be released as H+.

8.1.3 Deduce the formula of the conjugate acid (or base) of any BrØnsted-Lowry base (or acid).
Conjugate pairs - there is always a donor and acceptor
B-L theory - if an acid donates a H+ there is also a base present to accept the proton

Conjugate base pairs

Acids react to form bases (vice versa), therefore it is easy to predict the formula, the conjugate acid-base pairs differs by ONE proton.

e.g. H2O and H3O+ (found in all acid-base reactions in aqueous solutions)