Acid and Bases

Amy Holden
Mind Map by Amy Holden, updated more than 1 year ago
Amy Holden
Created by Amy Holden about 5 years ago
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Mind Map on Acid and Bases, created by Amy Holden on 10/04/2015.

Resource summary

Acid and Bases
1 Acid-base theories
1.1 Lewis
1.1.1 Acid - electron pair acceptor
1.1.2 Base - electron pair donor
1.2 Bronsted-Lowry
1.2.1 Acid - proton donor
1.2.2 Base - proton acceptor
2 Conjugate systems
2.1 Acids are related to bases
2.1.1 ACID <=> PROTON + CONJUGATE BASE
2.2 Bases are related to acids
2.2.1 BASE + PROTON <=> CONJUGATE ACID
2.3 For an acid to behave as an acid, it must have a base present to accept a proton
2.3.1 acid + base <=> conjugate base + conjugate acid
2.3.1.1 HA + B <=> BH+ + A-
3 pH = -log10[H+]
3.1 The smaller the pH, the greater the conc. of H+
4 pOH = -log10[OH-]
5 Kw = [H+][OH-]
5.1 water is weakly dissociated
6 Weak acids and bases
6.1 weak acids and weak bases dissociate only in aqueous solution
6.2 Ka = ([H+][A-]) / [HA]
6.2.1 Ka is the dissociation constant for a weak acid
6.2.2 Ka = [H+]2 / [HA]
6.3 The weaker the acid..
6.3.1 the less it dissociates
6.3.2 the fewer ions you get
6.3.3 the smaller Ka
6.4 pKa
6.4.1 very weak acids have very small Ka values
6.4.1.1 Its is easier to compare the strength as pKa
6.4.2 pKa = -log10 (Ka)
7 species that can act as an acid or base are amphoteric
8 Strong acids
8.1 a strong acid is one which dissociates completely in water into H+ and A-
8.2 Examples
8.2.1 HCl
8.2.2 HNO3
8.2.3 H2SO4
8.3 Strong acids do not dissociate fully at high concentrations
8.3.1 There is not enough water
8.3.2 diluting the acid tenfold causes the pH to increase by one unit
9 Titrations
9.1 Curves
9.2 Indicators
10 Buffers
10.1 A solution that resists change of pH when small amounts of acid or base are added or on dilution
10.2 Acidic buffers
10.2.1 They are made from a mixture of a weak acid and a soluble salt of that acid
10.2.2 It will maintain a pH of below 7
10.2.3 The weak acid component is to act as a source of HA to remove any added OH-
10.2.3.1 HA + OH- --> A- + H2O
10.2.4 The salt component is to act as a source of A- to remove any added H+
10.2.4.1 A- + H+ --> HA
10.3 It is possible to saturate a buffer
10.4 Basic buffers
10.4.1 It will maintain a pH of above 7
10.4.2 They are made from a mixture of a weak base and a soluble salt of that base
10.4.3 Aqueous ammonia and ammonium chloride acts as a bsic buffer
10.4.3.1 NH3 + H+ --> NH4+
10.4.3.2 NH4+ + OH- --> NH3 + H2O
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