Acid-base Equilibria

Question 1

How do you find the pH of a strong acid?

Answer 1

pH = -log10[H+]

Question 2

How do you find the pH of a weak acid?

Answer 2

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

Question 3

Define a strong acid

Answer 3

Fully dissociates in aqueous solution

Question 4

Define a weak acid

Answer 4

Partially dissociates in aqueous solution

Question 5

What is the equation for pKa?

Answer 5

pKa = -log10 Ka

Question 6

What is the equation for pKw?

Answer 6

pKw = -log10 Kw

Question 7

Which indicator has a pH range of 5-8?

Answer 7

Litmus

Question 8

Which indicator has a pH range of 3.1 - 4.4?

Answer 8

Methyl orange

Question 9

Which indicator has a pH range of 8.3 - 10?

Answer 9

Phenolphthalein

Question 10

What is a buffer solution?

Answer 10

A solution which resists changes in pH when a small amount of an acid or an alkali are added

Question 11

How do you make an acidic buffer solution?

Answer 11

Weak acid + it’s salt. Eg. Ethanoic acid and sodium ethanoate

Question 12

How do you make an alkaline buffer solution?

Answer 12

Weak base + it’s salt. Eg. Ammonia solution and ammonium chloride

Question 13

What is the Henderson-Hasselbalch equation?

Answer 13

pH = pKa + log10 ([A-] / [HA])

Question 14

What is an amphoteric substance?

Answer 14

Substance that can behave as both an acid and a base

Question 15

What is the definition of an acid?

Answer 15

Compound which can act as a proton donor

Question 16

What is the definition of a base?

Answer 16

Compound which can act as a proton acceptor

Question 17

What is an alkali?

Answer 17

A soluble base that produces OH- ions when added to water