Aqueous

Question 1

Kw is affected by temperature…how?

Answer 1

Dissociation of water is endothermic.

Therefore as temp increases, Kw increases.

Question 2

A large Ka value means it is a …

Answer 2

Stronger acid

Question 3

A small Ka value means it is a …

Answer 3

weaker acid

Question 4

Ka =

Answer 4

Ka = (conj. base) (h3o+) / (acid)

Question 5

Kb =

Answer 5

Ka x Kb = Kw OR Kb = (weak base)(OH-) / (conj. acid)

Question 6

A large Kb values means it is a …

Answer 6

Stronger base

Question 7

Pka of strong acids is…

Answer 7

negative

Question 8

As the strength of acids decreases

Answer 8

• Ka becomes smaller
• pKa becomes larger
• equilibrium conc. of h3o+ and conj. base of acid DECREASES
• strength of conjugate bases increase

Question 9

Relative equilibrium concentrations of neutral molecular solutions

Answer 9

Highest conc: water
2nd highest conc: solution itself (l)
3rd equal: small amount of H30+ and OH-

Question 10

Relative equilibrium concentrations of neutral molecular solutions

Answer 10

Highest conc: solution itself (l)

2nd equal: small amount of H30+ and OH-

Question 11

Relative equilibrium concentrations of strong acids

Answer 11

Complete dissociation occurs.
Highest equal: ACID IONS
2nd highest small: H3O+
Smallest amount of OH-

Question 12

Relative equilibrium concentrations of solutions of weak acids

Answer 12

1. Weak acid itself
   2 equal. = conj. base and h3o+
2. small amount OH-

Question 13

Relative equilibrium concentrations of solutions of weak bases

Answer 13

1. Weak base itself
2. equal conc. of conj. acid and OH-
3. small amount of H30+

Question 14

Relative equilibrium concentrations of neutral salts

Answer 14

1. equal –> salt ions
2. equal –> small amount of H3O+ and OH-

(KEEP MOLE RATIO IN MIND, DIRECTLY PROPORTIONAL)

Question 15

Relative equilibrium concentrations of acidic salts

Answer 15

1. equal conc. of acids salt ions
2. equal conc. of conjugate base and h3o+
3. small amount OH-

Question 16

Relative equilibrium concentrations of basic salts

Answer 16

1. equal conc. of base salt ions
2. equal conc. of conjugate acid and OH-
3. small amount of H3O+

Question 17

Solvent: cyclohexane

Answer 17

Non polar solvent.

Weak temp. dipole attractions between molecules.

Question 18

Solvent: ethanol

Answer 18

polar molecule.
acts as polar solvent due to OH group.
Also acts as non polar solvent to due nonpolar CH3CH2 group.

Question 19

A buffer solution contains…

Answer 19

Similar concentrations of either…

Weak acid and its conjugate base.
OR
Weak base and its conjugate acid.

Question 20

What is a buffer solution?

Answer 20

A buffer solution maintains a reasonably constant pH on the addition of small amounts of acid or base.

Question 21

What happens to a buffer when you add base?

Answer 21

The acid/conjugate acid part of buffer neutralises the added base. It donates protons. Forms water.

Question 22

What happens to a buffer when you add acid?

Answer 22

The base/conjugate base part of buffer neutralises the added acid. It accepts protons. Forms water.

Question 23

What happens when you dilute a buffer solution?

Answer 23

The pH stays unchanged. But the capacity is reduce, since there is now lower concentrations of acid and base.

Question 24

Relative equilibrium concentrations of strong bases

Answer 24

Complete dissociation occurs.
Highest equal: BASE IONS
2nd highest small: OH-
smallest amount of H3O+

Question 25

HCl

Answer 25

Strong acid

Question 26

HBr

Answer 26

strong acid

Question 27

HNO3

Answer 27

strong acid

Question 28

H2SO4

Answer 28

strong acid

Question 29

KOH

Answer 29

strong base

Question 30

NaOH

Answer 30

strong base

Question 31

HF

Answer 31

weak acid

Question 32

CH3COOH

Answer 32

weak acid

Question 33

NH4+

Answer 33

weak acid

Question 34

NH3

Answer 34

weak base

Question 35

CH3NH2

Answer 35

weak base

Question 36

CH3COO-

Answer 36

weak base