Acids And Bases Part 1

Question 1

What does bronsted Lowry theory describe acids and bases in terms of

Answer 1

Protons

Question 2

What does an acid-base reaction involve

Answer 2

Proton transfer

Question 3

Acid

Answer 3

A substance that donates H+ ions

Question 4

What are acids classified as strong or weak depending on

Answer 4

The extent of dissociation

Question 5

Strong acid

Answer 5

Completely dissociates in solution

Question 6

Weak acid

Answer 6

Partially dissociates in solution

Question 7

Base

Answer 7

A substance that accepts H+ ions

Question 8

Alkali

Answer 8

A base that releases hydroxide ions in aqueous solution

Question 9

What type of reaction is that of acids with metals

Answer 9

Redox

Question 10

What is the role of H+ ions in the reaction of acids with metals

Answer 10

Oxidising agent

Question 11

What are acid base equilibria

Answer 11

Reversible reactions involving the transfer of protons

Question 12

pH

Answer 12

-log[H+]

Question 13

What does a low pH mean

Answer 13

Larger concentration of H+ ions

Question 14

What does a high pH mean

Answer 14

A small concentration of H+ ions

Question 15

[H+]

Answer 15

10 ttp -pH

Question 16

How many moles of H+ ions does one mole of a monoprotic acid donate

Answer 16

One mole

Question 17

What do you assume in pH calculations for strong acids

Answer 17

Complete ionisation

Question 18

What does it mean that for pH calculations of strong acids, you assume complete ionisation

Answer 18

[H+]=original conc of acid

Question 19

Is sulfuric monoprotic

Answer 19

Diprotic

[H+]=2[HA]

Question 20

What are a weak acids undissociated molecules in equilibrium with

Answer 20

It’s ions

Question 21

Acid dissociation constant

Answer 21

Ka

Question 22

Ka

Answer 22

Conc product/conc reactants

Question 23

Units of Ka

Answer 23

Moldm-3

Question 24

What is the value of Ka a quantitative measure of

Answer 24

The strength of a weak acid

Question 25

What is the relationship between degree of dissociation and Ka value and why

Answer 25

Greater degree of dissociation, higher conc of H+ and larger Ka value

Question 26

What is pKa sometimes used for

Answer 26

To compare the relative strengths of acids

Question 27

pKa

Answer 27

-logKa

Question 28

Relationship between Ka value and strength of acid

Answer 28

Higher Ka value = stronger acid

Question 29

Relationship between pKa value and acid strength

Answer 29

Lower pKa value = stronger acid

Question 30

Expression for ionisation of water

Answer 30

h20 > H+ + OH-

Question 31

To what extent does pure water ionise to

Answer 31

A very small extent

Question 32

What is Kw derived from

Answer 32

The equilibrium constant for the dissociation of water into H+ ions and OH-

Question 33

Definition of Kw

Answer 33

[H+][OH]

Question 34

What is Kw at 298K

Answer 34

1x10-14 mol2dm-6

Question 35

Why is the dissociation of water an endothermic process

Answer 35

Energy is required to break bonds

Question 36

Why does Kw increase when temperature increases

Answer 36

The equilibrium moves to the right

Question 37

Assumptions to make to calculate the pH of a strong base

Answer 37

• assume complete ionisation

- assume Kw= 1x10-14