Topic 14: Acids, Bases, Buffers and Solubility 2

Question 1

Polyprotic acid

Answer 1

Acids that can lose more than 1 proton

Question 2

Each successive proton is .. to remove even if proton are …

Answer 2

harder
equivalent

Question 3

At buffer point [A^-] and [HA] are …
pH =

Answer 3

in equal amounts
(pKa1 + pKa2) / 2

Question 4

Lewis acid (A)

Answer 4

electron pair acceptor

Question 5

Lewis base (B)

Answer 5

electron pair donor

Question 6

3 types of Lewis acid

Answer 6

Molecules with an incomplete octet of valance electrons, completed by accepting an electron pair
A metal cation, which accepts an electron pair supplied by the base
A molecule or ion with a complete octet that can rearrange valence
electrons and accept an electron pair.
Lewis baseLewis acid complex adduct
A molecule or ion that can expand its valence shell (or be large
enough) to accept another electron pair

Question 7

Dissolution (dissolving) of a material occurs when

Answer 7

the free energy required to disrupt the lattice bonding (ΔGL ) is offset by the free energy released in the formation of aqueous species

Question 8

solubility

Answer 8

The amount of solid (g or mol) that dissolves in a given volume of solvent (dm3)

Question 9

The solubility product (Ksp)

Answer 9

an equilibrium constant that is related to the solubility of a salt in a solvent

Question 10

K sp =

Answer 10

[M+]^a[X-]^b

Question 11

MaXb (s) <=>

Answer 11

aM^+(aq) + bX^-(aq)

Question 12

The common-ion effect

Answer 12

If a salt MX (e.g. NaCl) is added to an aqueous solution containing the solute MY (e.g. NaBr), e.g. the ion M+ is common to both salts the presence of the originally dissolved M+ ions
suppresses the dissolution of MX compared with that in pure water
Same effect if there is a common anion
e.g. AgCl will be more soluble in water than in KCl solution