Topic 3:Acids And Alkalis Flashcards

1
Q

What is the chemical symbol and charge for sulphate ion

A

SO4 , 2-

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

What is the chemical symbol and charge for carbonate ion

A

CO3 , 2-

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

What is the chemical symbol and charge for nitrate ion

A

NO3 , 1-

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

What is the chemical symbol and charge for hydroxide ion

A

OH , 1-

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

What is the chemical symbol and charge for phosphate ion

A

PO4 , 3-

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

What is the chemical symbol and charge for ammonium ion

A

NH4 , 1+

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

What are the 6 polyatomic ions?

A
Sulphate
Carbonate
Phosphate
Hydroxide
Nitrate
Ammonium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What rage of number is the pH of acids?

A

Less than 7

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

What rage of numbers is the pH of alkalis?

A

More than 7

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

What are acids formed from?

A

Compounds that contain hydrogen

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

What happens when the compound is dissolved in water?

A

They split into hydrogen ions

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

What is the concentration?

A

Amount of substance per unit volume of solvent

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

What does high pH mean?

A

Low concentration

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

What is the end point?

A

The points at which the indicator changes colour

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

What are indicators?

A

Substances that change colour at a certain pH

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

What is the equation for concentration?

A

Concentration = mass/volume

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

What is concentration measured in?

A

g/dm3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is volume measure in?

A

Dm3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What happens as the concentration is increased by a factor of 10?

A

The pH goes down by 1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How are strong acids formed?

A

From compounds that split up (dissociate) completely into ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

3 examples of strong acids

A

Hydrochloric acid
Sulphuric acid
Nitric acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What happens to weak acids?

A

They do not fully dissociate, only some molecule split up to release hydrogen ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

1 example of a weak acid

A

Ethanoic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are bases?

A

Metal oxides and hydroxides, any substance that reacts with an acid to form a salt and water only

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What can bases do?

A

Neutralise acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Which bases are soluble?

A

Only the alkali bases, the rest are insoluble

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is produced when a base reacts with an acid?

A

Salt and water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Example of a word equation of a reaction between magnesium oxide and hydrochloric acids

A

Magnesium oxide + hydrochloric acid —> magnesium chloride + water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is pH neutral?

A

pH 7

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What happens as the concentration of hydrogen ions increases?

A

The pH decreases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is an indicator?

A

A dye that change colour depending on whether it’s above or below a certain pH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is the reaction between an acid and a base called?

A

Neutralisation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What happens to the products when neutralisation happens?

A

They become neutral, pH 7

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What is titration?

A

A very accurate technique for adding acid to alkali

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What do strong acids do in water?

A

Ionise almost completely

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What does ionising in water mean?

A

A large portion of the acid molecules dissociate to release H+ ions - tend to have low pH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What happens to week acids in solutions?

A

They do not fully ionise in solution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What does it mean if acids don’t fully ionise in solutions?

A

Only a small proportion of the acid molecules dissociate to release H+ ions - tend to be around 2-6 pH

39
Q

What are alkalis in solution sources of

A

Hydroxide ions

40
Q

Do acids have high or low pH

A

Low

41
Q

What does the higher the concentration of hydrogen ions mean in an acidic solution

A

The lower the pH

42
Q

What does the higher the concentration of hydroxide ions in an alkali solution mean

A

The higher the pH

43
Q

What happens with an acid-alkali neutralisation

A

Hydrogen ions (H+) from the acid react with hydroxide ions (OH-) from the alkali to form water

44
Q

What does a dilute acid mean

A

An acid with a small number of acid molecules compared to the volume of water

45
Q

What is a concentrated acid

A

An acid with large number of acid molecules compared to the volume of water

46
Q

What colour is litmus when there’s an acid present

A

Red

47
Q

What colour is litmus in a neutral solution present

A

Purple

48
Q

What colour is litmus in a alkaline solution present

A

Blue

49
Q

What colour is methyl orange in a neutral and alkaline solution present

A

Yellow

50
Q

What colour is methyl orange in an acidic solution present

A

Red

51
Q

What colour is phenolphthalein in a neutral and acidic solution present

A

Colourless

52
Q

What colour is phenolphthalein in an alkaline solution

A

Pink

53
Q

What type of reaction is the ionisation of a weak acid

A

Reversible

54
Q

What is concentration measured in

A

g dm(-3) or mol dm(-3)

55
Q

What are salts

A

Ionic compounds

56
Q

What does an acid + metal make

A

Salt + water

57
Q

What does acid + metal hydroxide make

A

Salt + water

58
Q

What does an acid + metal make

A

Salt + hydrogen

59
Q

What does an acid + metal carbonate make

A

Salt + water + carbon dioxide

60
Q

What substances are soluble?

A

Common salts-sodium, potassium, ammonium
Nitrates
Common chlorides (except sliver&lead chloride)
Common sulfates(except lead,barium,calcium sulfate)

61
Q

What substances are insoluble

A

Silver&lead chloride, lead&barium&calcium sulfate, common carbonates and hydroxides(except sodium&potassium&ammonium ones)

62
Q

How can u make a pure dry sample of an insoluble salt

A

Precipitation reaction

63
Q

Why is an excess of the reactant used in making soluble salts using an acid and insoluble base

A

So that u don’t have any leftover acid in your product

64
Q

Why is the excess recant at removed when making a soluble salt from and acid and an insoluble base

A

To get the solution containing only salt and water

65
Q

Why is titration used if soluble salts are prepared from an acid and a soluble reactant

A

U need work out exactly the right amount of alkali to neutralise the acid

66
Q

What are electrolytes

A

Ionic compounds in the molten state or dissolved in water

67
Q

What is electrolysis

A

A process in which electrical energy, from a direct current supply, decomposes electrolytes

68
Q

Where do positively charged cations go during electrolysis

A

Migrate to the negatively charged cathode

69
Q

When do negatively charged anions migrate to during electrolysis

A

The positively charged anode

70
Q

What does OIL RIG stand for

A

Oxidation is loss

Reduction is gain

71
Q

WHats an electrochemical cell

A

A circuit that is made up of the anode, cathode, electrolyte a power source and the wires that connect the 2 electrode

72
Q

How do u write half equations

A

1) put one of the things being oxidised or reduced on one side of an arrow and thr thing that gets oxidised or reduced to on the other
2) balance up the numbers of atoms
3) all the electrons (e(-)) on to one side to balance charges

73
Q

Half equation of sodium loosing 1 electron to become a sodium ion

A

Na — Na(+) + e(-)

74
Q

Why can’t ionic solids be electrolysed

A

Because the ions are in fixed positions and can’t mive

75
Q

What will be produced at the cathode if H(+) and metal ions are present

A

Hydrogen will be produced

76
Q

What happens if the metal is less reactive than hydrogen at the cathode

A

Solid layer of thr pure metal will be produced

77
Q

What happens if At the anode is OH(-) and halide ions (Cl(-), Br(-)) are present

A

then molecules of chlorine, brownie or iodine will be formed

78
Q

What happens at the anode of no halide ions are present

A

O2 is form3

79
Q

How do you make a soluble salt from an acid and an insoluble base

A

1) heat the acid in a water bath (speeds up the reaction between the acid and the insoluble base, do in a fume cupboard to avoid releasing acid fumes into room)
2) add the base to the acid-base and acid react to produce a soluble salt and water(when base is in excess-excess solid will sink to bottom of flask)
3) filter off the excess solid to get a solution only containing salt and water
4) heat the solution gently over a Bunsen burner to slowly evaporate some of the water, leave to dry and cool and salt will crystallise, filter off the solid salt and leave to dry

80
Q

How do u do the titration of a soluble salt using an acid/alkali reaction

A

1) use a pipette to measure out amount of acid into conical flask. Add few drops of iniciaron
2) slowly add alkali to the acid using a bureta until u reach the end point(when acids been exactly neutralised and indicator changes colour)
3) then carry out the reaction using the same volumes of alkali and acid with no indicator - so salt isn’t contaminated with indicator
4) when reaction is complete only salt and water will be left
5) slowly evaporate some of the water and leave solution to crystallise- filter off the solid leave to dry and have pure dry salt

81
Q

Steps of how to make a pure dry sample of an insoluble salt

A

1) add a spatula of lead nitrate to a test tube, add water to dissolve it(deionised), shake thoroughly to make sure all lead nitrate has dissolved. In separate test tube do same with spatula of sodium chloride
2) tip the 2 solutions into a small beaker and mix, the lead chloride should precipitate out
3) filter the contents of beaker into a conical flask
4) swill out the beaker with more deionised water and tip into filter paper
5) scrape lead chloride onto fresh filter paper and leave to dry in an oven of desiccator

82
Q

What product is formed at the cathode when using the aqueous electrolyte copper chloride

A

Copper

83
Q

What product is formed at the cathode when using the aqueous electrolyte sodium sulfate

A

Hydrogen

84
Q

What product is formed at the cathode when using the aqueous electrolyte water acidified with sulfuric acid

A

Hydrogen

85
Q

What product is formed at the anode when using the aqueous electrolyte copper chloride

A

Chlorine

86
Q

What product is formed at the anode when using the aqueous electrolyte sodium sulfate

A

Oxygen

87
Q

What product is formed at the anode when using the aqueous electrolyte water acidified with sulfuric acid

A

Oxygen

88
Q

What is formed at the cathode in the electrolysis of copper sulfate with inert electrodes

A

Copper metal

89
Q

What is formed at the anode from the electrolysis of copper sulfate using inert electrodes

A

Oxygen and water

90
Q

What happens at the anode from electrolysis of copper sulfate using copper (non inert) electrodes

A

The mass of the anode decreases

91
Q

What happens at the cathode from electrolysis of copper sulfate using copper (non inert) electrodes

A

Mass of the cathode increases

92
Q

What do u need to purify copper by electrolysis

A

An electrochemical cell, copper electrodes

93
Q

What happens during the process of purifying copper

A

1) the impure copper anode is oxidised , dissolving into the electrolyte to form copper ions
2) the copper ions are reduce at the pure copper cathode and add to its layer of pure copper
3) any impurities from the impure copper anode sink to the bottom of the cell forming a sludge