Acid Base Equilibria

Question 1

What’s a Brønsted-Lowry acid?

Answer 1

A proton donator

Question 2

What’s a Brønsted-Lowry base?

Answer 2

A proton acceptor

Question 3

What’s the definition for a strong acid?

Answer 3

An acid that completely dissociates to ions when in a solution with a pH of 0-1

Question 4

Define a weak acid.

Answer 4

An acid that only slightly dissociates in a solution with pH 3-7

Question 5

Why does an equilibrium form when reacting weak acids/bases?

Answer 5

They only slightly dissociate

Question 6

What’s the equation for determining pH of a strong acid/base?

Answer 6

pH = -log10[H+]

Question 7

What’s the equation for weak acid?

Answer 7

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

Question 8

What’s the equation for the ionic product of water?

Answer 8

Kw = [H+][OH-]

Question 9

Is the reversible reaction of H2O to its ions endo or exo
H2O ⇌ H+ + OH-

Answer 9

The forward reaction is endothermic, so when temperature increases system shifts to the right, therefore becomes more acidic.

Question 10

What’s the neutralisation point of a titration curve?

Answer 10

A large verticals section of the graph

Question 11

How do you make a titration curve more accurate?

Answer 11

Add smaller volume of acids and bases

Question 12

Where does the neutralisation point occur for each combination of strong/weak acid/base?

Answer 12

Strong acid + strong base = 7
Strong acid + weak base <7
Weak acid + Strong base > 7
Weak acid + Weak base = N/A

Question 13

At the equivalence point thr pH is equal to pKa (True/False)

Answer 13

False, occurs at half equivalence point

Question 14

How is a buffer formed?

Answer 14

A weak acid and its salt
Or a weak acid and a base

Question 15

Why do buffers resist any change in pH?

Answer 15

A mixture of H+ ions and a large reservoir of OH- ions are produced

Question 16

What is a buffer solution?

Answer 16

A solution which is able to resist changes in pH when small volumes of acid or base are added

Question 17

What’s a Homogenous equilibrium

Answer 17

Reactions in which the reactants and products are in the same phase/state

Question 18

What’s the equation for partial pressure

Answer 18

(Moles of X / Total moles) * Total Pressure

Question 19

Does concentration/pressure affect Kc or amp

Answer 19

No it doesn’t

Question 20

What’s the effect of using a catalyst on Kc and Kp

Answer 20

No effect

Question 21

What are two assumptions when using Ka?

Answer 21

No H+ ions arrive from thr ionisation of water.
No H+ ions arrive from the dissociation of the weak acid. Initial = equlibrium

Question 22

What does amphoteric mean?

Answer 22

A substance that reacts with both acids and bases (accepts or donates electrons)