Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

A - Level Chemistry > Chapter 20 Acids, Bases And pH > Flashcards

Chapter 20 Acids, Bases And pH Flashcards

You may prefer our related Brainscape-certified flashcards:
Periodic Table flashcards Chemistry 101 flashcards AP® Chemistry flashcards Organic Chemistry 101 flashcards
1
Q

Define a Bronsted-Lowry acid

A

Proton donor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Define a Bronsted-Lowry base

A

Proton acceptor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What ion causes a solution to become acidic? (2 marks) Name and formula

A

H+ or more accurately H3O+ as protons react with H2O to form it.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What ion causes a solution to be alkaline?

A

-OH (hydroxide ion)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Write the equation for the ionisation of water

A

2H2O (l) (reversible reaction) H3O+(aq) + -OH(aq)

H2O (l) (reversible reaction) H+(aq) + -OH(aq)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Give an example of a monobasic acid.

A

HCl

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Give example of a dibasic acid

A

H2SO4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Give an example of a tribasic acid

A

H3PO4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Define a strong acid

A

An acid that completely dissociates in (aq) to release H+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Give examples of strong acids

A

HCl

H2SO4

HNO3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the difference between concentrated and strong?

A

Concentrated means many mol per dm3

Strong refers to amount of dissociation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Define weak acid

A

An acid that only partially dissociates in aq to release H+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Give examples of weak acids

A

Methanoic acid

Any organic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the constant that is used to measure the extent of acid dissociation called?

A

Acid dissociation constant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the symbol of acid dissociation constant?

A

Ka

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What does a larger Ka value mean?

A

Larger the Ka - greater the extent of dissociation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Write the equation used to convert Ka into pKa.

A

pKa = -log(Ka)

18
Q

Write the equation used to convert pKa into Ka.

A

Ka = 10^-pKa

19
Q

What is the relationship between pKa and the strength of the acid?

A

Smaller the pKa stronger the acid

20
Q

What is the equation used to convert concentration of H+ into pH.

A

pH = -log[H+]

21
Q

Write the equation used to convert pH into concentration of H+

A

[H+] = 10^-pH

22
Q

Why is the pH scale useful compared to concentration of H+?

A

pH scale allows a wide range of H+ concentration to be expressed as simple positive values.

23
Q

What is the relationship between pH and [H+]?

A

High pH value means a small [H+]

24
Q

If two solutions have a pH difference of 1, what is the difference in [H+]?

A

A factor of 10

25
Q

[H+] of a strong acid is equal to what?

A

[H+] = [HA]

26
Q

What is the assumption made when calculating pH of weak acids?

A

It is assumed that the concentration of acid at equilibrium is equal to the concentration of acid after dissociation. This is because only very little of the acid dissociates.

27
Q

Write the expression for the ionic product of water, Kw

A

Kw = [H+][OH-]

28
Q

What is the units for Kw?

A

Mol^2dm^-6

29
Q

What is the value of Kw at 298K?

A

1.0 x 10^-14

30
Q

What physical factors affect the value of Kw? How do they affect it?

A

Temperature only - if temperature is increased, the equilibrium moves to the right so Kw increases and the pH of pure water decreases.

31
Q

Indices of [H+] and [OH-] always add up to what value?

A

-14

32
Q

Define the term strong base

A

Base that dissociates 100% in water

33
Q

Give examples of strong bases

A

NaOH

KOH

Ca(OH)2

34
Q

Give an example of a weak base

A

Ammonia

35
Q

Write the equation used to calculate [H+] of strong bases

A

[H+] = Kw / [OH-]

36
Q

Define a salt

A

The product of a reaction in which the H+ ions from the acid are replaced by metal or ammonium ions.

PMT = a compound that is formed when H+ of an ion is replaced by a metal ion or positive ion.

37
Q

What is the definition of Kw?

A

The temperature dependent constant that represents the dissociation of water into H+ and OH-.

38
Q

Define strength of acids and bases

A

A measure of the relative degree of dissociation of an acid or base (where strong means complete dissociation and weak means partial dissociation).

39
Q

Define a conjugate acid-base pair

A

Contains 2 species that can be interconverted by transfer of a proton.

40
Q

Define an alkali

A

A soluble base that dissociate in aq to release OH-

41
Q

Define a base

A

An insoluble compound that neutralises an acid to form a salt.

42
Q

Define Ka

A

The equilibrium constant that shows the extent of dissociation of a weak acid.

A - Level Chemistry (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions