Acids And Bases - Inorganic Chemistry

Front 1

Water is ____ - it can act as either a Brønsted-Lowry acid or a Brønsted-Lowry base.

Back 1

Water is amphiprotic - it can act as either a Brønsted-Lowry acid or a Brønsted-Lowry base.

Front 2

Define an aqua acid.

Back 2

A water molecule coordinated to a central metal ion.

Front 3

Define a hydroxoacid.

Back 3

A hydroxyl group bound to a central atom.

Front 4

Define an oxoacid.

Back 4

A hydroxyl group with an oxido group attached to the same atom.

Front 5

Determine structures for A and B.

Back 5

Front 6

Aqua acid strength increases with increasing ____ ____ of the central ion and decreasing ____ ____ of the central ion.

Back 6

Aqua acid strength increases with increasing positive charge of the central ion and decreasing ionic radius of the central ion.

Front 7

In the ionic model, ____ repulsion between the central ion and H{+} predicts a linear relationship between the ____ ____ (given symbol ____) and ____.

Back 7

In the ionic model, electrostatic repulsion between the central ion and H{+} predicts a linear relationship between the electrostatic parameter (given symbol ξ) and pK[A].

Front 8

A strong ____ interaction results in deviation from the ionic model due to increased ____ ____ on the oxygen atom, increasing repulsion.

Back 8

A strong covalent interaction results in deviation from the ionic model due to increased positive charge on the oxygen atom, increasing repulsion.

Front 9

State Pauling's first rule.

Back 9

For the acid O[p]E(OH)[q] (where E is the central atom):

pK[A] ≈ 8 - 5p

Front 10

State Pauling's second rule.

Back 10

For the acid O[p]E(OH)[q] (where E is the central atom):

pK[A] is increased by ~5 for each successive deprotonation (decrease in q)

Front 11

Which is a stronger acid, A or B?

Back 11

B

Front 12

What pK[A] do Pauling's rules predict for this molecule?

Back 12

3

Front 13

The experimental equilibrium constant for the deprotonation of this molecule in aqueous solution is 7.94 x 10{-3}. What is the pK[A]?

Back 13

2.10

Front 14

Oxoacid strength ____ with increasingly electron withdrawing substituents on the central atom.

Back 14

Oxoacid strength increases with increasingly electron withdrawing substituents on the central atom.

Front 15

Which is a stronger acid, H[3]PO[4] or H[3]PO[3]?

Back 15

H[3]PO[4]

Front 16

____ anhydrous oxides have a non-metallic central atom. Hydration of these releases a ____. ____ anhydrous oxides have a metallic central atom. Hydration of these releases a ____ ion.

Back 16

Acidic anhydrous oxides have a non-metallic central atom. Hydration of these releases a proton. Basic anhydrous oxides have a metallic central atom. Hydration of these releases a hydroxide ion.

Front 17

Define an amphoteric oxide.

Back 17

Amphoteric oxides react with both acids and bases.

Front 18

Amphoterism of an anhydrous oxide varies with the ____ ____ of the central atom.

Back 18

Amphoterism of an anhydrous oxide varies with the oxidation state of the central atom.

Front 19

Why is the experimental pK[A] of carbonic acid 6.4 when Pauling's rules predict it to be 3?

Back 19

Most carbonic acid is actually in the form of carbon dioxide, so its real concentration is lower than expected. Using this real concentration in the pK[A] calculation would give a pK[A] value closer to 3.

Front 20

Condensation reactions release water and lead to the formation of ____ compounds.

Back 20

Condensation reactions release water and lead to the formation of polyoxo compounds.

Front 21

Aqua ions form polymers as the pH is ____.

Back 21

Aqua ions form polymers as the pH is increased.

Front 22

Oxoanions form polymers as the pH is ____.

Back 22

Oxoanions form polymers as the pH is decreased.

Front 23

Polyoxo compounds ____ from solution at a given pH. This can then be ____ for removal of metal ions from solution.

Back 23

Polyoxo compounds precipitate from solution at a given pH. This can then be crystallised for removal of metal ions from solution.

Front 24

What are the products of this reaction?

Back 24

Front 25

Identify the Lewis acid and the Lewis base. What is the product of this reaction?

Back 25

Trimethylborane is the Lewis acid.

Ammonia is the Lewis base.

Front 26

Unlike Brønsted-Lowry theory, Lewis theory can also be applied to ____ and non-____ systems.

Back 26

Unlike Brønsted-Lowry theory, Lewis theory can also be applied to aprotic and non-aqueous systems.

Front 27

A molecule with an incomplete ____ can complete it by accepting an electron pair.

Back 27

A molecule with an incomplete octet can complete it by accepting an electron pair.

Front 28

A metal cation can bond to an electron pair supplied by the base in a ____ compound.

Back 28

A metal cation can bond to an electron pair supplied by the base in a coordination compound.

Front 29

A molecule or ion with a complete octet may be able to rearrange its ____ electrons and accept an additional electron pair.

Back 29

A molecule or ion with a complete octet may be able to rearrange its valence electrons and accept an additional electron pair.

Front 30

An atom with a complete octet which is large enough to still accept further electron pairs is known as ____.

Back 30

An atom with a complete octet which is large enough to still accept further electron pairs is known as hypervalent.

Front 31

The orbitals involved in Lewis pair formation are the ____ orbitals.

Back 31

The orbitals involved in Lewis pair formation are the frontier orbitals.

Front 32

The ____ ____ molecular orbital of the Lewis base interacts with the ____ ____ molecular orbital of the Lewis acid.

Back 32

The highest occupied molecular orbital (HOMO) of the Lewis base interacts with the lowest unoccupied molecular orbital (LUMO) of the Lewis acid.

Front 33

Define complex formation.

Back 33

A free Lewis acid and free Lewis base become linked by a coordinate bond.

Front 34

Define displacement.

Back 34

An acid or base drives out another acid or base to form a new Lewis complex.

Front 35

Define metathesis.

Back 35

A reaction where two complexes swap bases and acids. This is two simultaneous displacement reactions.

Front 36

Is this reaction complex formation, displacement or metathesis?

Back 36

Displacement

Front 37

Is this reaction complex formation, displacement or metathesis?

Back 37

Complex formation

Front 38

Is this reaction complex formation, displacement or metathesis?

Back 38

Metathesis

Front 39

Is this reaction complex formation, displacement or metathesis?

Back 39

Metathesis

Front 40

____ acids and bases are small and non-polarisable and form predominantly ____ bonds. ____ acids and bases are larger and more polarisable and form predominantly ____ bonds. In general, hardness ____ down a group. This is known as ____ theory.

Back 40

Hard acids and bases are small and non-polarisable and form predominantly electrostatic/ionic bonds. Soft acids and bases are larger and more polarisable and form predominantly covalent bonds. In general, hardness decreases down a group. This is known as Pearson's theory.

Front 41

____ acids form complexes with stabilities in the order I{-} < Br{-} < Cl{-} < F{-}. ____ acids form complexes with stabilities in the order F{-} < Cl{-} < Br{-} < I{-}.

Back 41

Hard acids form complexes with stabilities in the order I{-} < Br{-} < Cl{-} < F{-}. Soft acids form complexes with stabilities in the order F{-} < Cl{-} < Br{-} < I{-}.

Front 42

____ acids form complexes with stabilities in the order R[2]O << R[3]S, R[3]N << R[3]P. ____ acids form complexes with stabilities in the order R[3]P << R[3]N, R[3]S << R[2]O.

Back 42

Soft acids form complexes with stabilities in the order R[2]O << R[3]S, R[3]N << R[3]P. Hard acids form complexes with stabilities in the order R[3]P << R[3]N, R[3]S << R[2]O.

Front 43

____ acids have a relatively small HOMO/LUMO energy gap than compared to ____ acids.

Back 43

Soft acids have a relatively small HOMO/LUMO energy gap than compared to hard acids.

Front 44

State three factors affecting the rate/yield of complex formation reactions in solution other than hard-hard and soft-soft interactions.

Back 44

1) Competition with the solvent.

2) Energy required for rearrangement of the substituents.

3) Steric repulsion between substituents on the acid and base.

Front 45

State the Drago-Wayland equation.

Back 45

Where:

E = electrostatic parameter

C = covalent parameter

Front 46

State two limitations of the Drago-Wayland equation to predict complex formation enthalpies.

Back 46

1) Semi-empircal model - predicts ΔH[f] to within±3 kJ mol{-1}.

2) Limited to reactions which occur in the gas phase or non-coordinating solvents (therefore mostly neutral molecules).

Front 47

Which Lewis base forms the more favourable complex with antimony pentachloride: ammonia or dimethylsulphide?

Back 47

ΔH[f] for ammonia = -116 kJ mol{-1}

ΔH[f] for dimethylsulphide = -171 kJ mol{-1}

Therefore dimethylsulphide complex more favourable.

Front 48

Describe the levelling effect.

Back 48

Solvents themselves can be acidic or basic in comparison to water, and this can affect the ability to discriminate between the acidity/basicity of dissolved molecules.

Front 49

A solvent with a large ____ ____ can be used to discriminate between a wide range of Brønsted-Lowry acid and base strengths.

Back 49

A solvent with a large autoprotolysis constant can be used to discriminate between a wide range of Brønsted-Lowry acid and base strengths.

Front 50

State a chemical equation for the autoprotolysis of ammonia.

Back 50

Front 51

What type of reaction is this?

Back 51

Autoionisation

Front 52

Solvent acidity affects the ____ and ____ of solutes.

Back 52

Solvent acidity affects the solubility and reactivity of solutes.

Front 53

Solvent polarity affects its ____ and ____ properties.

Back 53

Solvent polarity affects its acidity and solvation properties.

Front 54

____, ____ solvents are the most common type and can form Lewis complexes or perform displacement reactions with a solute.

Back 54

Basic, polar solvents are the most common type and can form Lewis complexes or perform displacement reactions with a solute.