Summary Acids and Redox Booklet

AS level Chemistry
OCR (Chemistry A – H032, H432)




Acids and Redox

Includes:
Acids
Bases
Neutralisations
Titrations
Preparing standards
Acid-base titration method


Redox

, Acids

Definition
Acids: ………………………………………………………………………………………………………………….
Strong Acid: ………………………………………………………………………………………………………………….
Weak Acid: …………………………………………………………………………………………………………………..

Common acids that you will have come across already through science are:

Hydrochloric Acid ……………
Sulphuric Acid ……………
Nitric Acid ……………
Phosphoric Acid ……………
Ethanoic Acid (vinegar) ……………

When an acid dissociates the H+ is left in the solution:
HCl (aq)  H+ (aq) + Cl- (aq)
H2SO4 (aq)  2H+ (aq) + SO42- (aq)

Water in the solution is always in excess.


Acids can come with different strengths: strong and weak.
Strong acids, like the 2 examples above, the H+ completely dissociates.
Weak acids, like in the example below, however only partially dissociates in a
solution. This means only a small amount of the H+ ions in the compound are
separated.

CH3COOH (aq) H+ (aq) + CH3COO- (aq)

The equilibrium symbol is used as the reaction is not complete, and there is both a
forward and a backward reaction.
There are 4 possible hydrogen atoms that could dissociate from the ethanoic acid,
however only 1 does, and this also does not happen in all ethanoic acid compounds.