Equlibria A Level

Question 1

Bronsted-lowry acid

Answer 1

proton donor

Question 2

Bronsted-lowry base

Answer 2

proton acceptor

Question 3

Monoprotic acid

Answer 3

donates 1 mole of protons per mole of acid

Question 4

Diprotic acid

Answer 4

Donated 2 moles of proton per mole of acid

Question 5

Degree of dissociation

Answer 5

fraction or percentage of molecules that dissociate into ions.

Question 6

Kw

Answer 6

Kw=[H+] [OH-]

Question 7

Ka

Answer 7

Ka= [H+][A-] / [HA]

Question 8

pH of buffer solution

Answer 8

pH= pKa +log[salt]/[acid]

Question 9

pH

Answer 9

pH=-log[H+]

Question 10

pH of weak acids

Answer 10

pH=root(Ka × [HA])

Question 11

What are Buffer solutions

Answer 11

Solutions that resist changes in pH when small amounts of acid or base is added

Question 12

Why does Kw vary with temperature

Answer 12

• forward reaction of the dissociation of water is endothermic.
• increase in temperature favours the endothermic reaction.
• [H+] and [OH-] increase
• hence Kw increases

Question 13

Neutral salt

Answer 13

strong acid + strong base

Question 14

Acidic salt

Answer 14

strong acid + weak base

Question 15

Basic salt

Answer 15

strong base + weak acid

Question 16

Amphotheric / Neutral salts

Answer 16

weak acid + weak base

Question 17

reaction quotient (Q)

Answer 17

determine if a precipitate will form with a given concentration of ions.
QKsp ~ precipitate will form

Question 18

Kpc

Answer 18

Kpc= [X in organic] / [X in aqueous]

Question 19

What is a buffer solution made of

Answer 19

weak acid with its conjugate base

weak base with conjugate acid

Question 20

Buffer solution in blood

Answer 20

H2CO3 <=> HCO3- + H+

Question 21

Other uses of buffer

Answer 21

baby lotion
shampoo
eyedrops