C5 - Chemical Changes Flashcards

1
Q

What happens when metals react with other substances

A

The metal atoms form positive ions

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

What is the reactivity of a metal related to

A

To its tendency to form positive ions

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

How can the metals be ordered by their reactions with water and dilute acid

A

They can be ordered in the reactivity series.

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

What non-metals are often included in the reactivity series

A

Hydrogen and carbon

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

What can happen when a more reactive metal reacts with a less reactive metal

A

more reactive metal can displace a less reactive metal from a compound.

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

Order the reactivity series (which you are required to know)

A

potassium, sodium, lithium, calcium, magnesium, zinc, iron, copper

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

What metals in the reactivity series react with water (fizz with cold water)

A

potassium, sodium, lithium, calcium, magnesium, (magnesium and higher)

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

What metals in the reactivity series react with a dilute acid

A

potassium, sodium, lithium, calcium, magnesium, zinc, iron (above but not including copper)

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

What gas is given off if metals react with water or dilute acids

A

Hyrdogen gas

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

How are unreactive metals found (e.g gold)

A

In the earth as the metal itself

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

How are more reactive (most) metals found

A

as compounds that require chemical reactions to extract the metal.

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

How can Metals less reactive than carbon be extracted

A

Extracted from their oxides by reduction with carbon.

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

What is oxidation

A

The loss of electrons

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

What is reduction

A

Gain of electrons

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

In this ionic equation which element has been oxidised and which reduced

Fe(s)+Cu^2+(aq) -> Fe^2(aq)+Cu(s)

A

Iron oxidised

Copper reduced

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

What does the reaction between metal and an acid produce aswell as salt

A

Hydrogen gas

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

What is a redox reaction

A

A reaction with involves oxidisation and reduction

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

What is a salt

A

A compound formed when the hydrogen in an acid is wholly or partially replaced by metal or ammonium ions.

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

How can salts be made

A

Reacting a suitable metal with an acid. The metal must be above hydrogen in the reactivity series, but not dangerously reactive

20
Q

What do all acid have

A

Hydrogen

21
Q

What determins the salt you make

A

The metal you use, as well as the acid

22
Q

What does the acid provide

A

The negative ions present in all salts

e.g sulfuric acid H^2SO^4 makes sulfates

23
Q

What is the reaction between a metal and an acid an example of

A

A redox reaction

24
Q

What is oxidised and what is reduced in a reaction between a metal and an acid

A

The metal atoms lose electrons and are oxidised, and the hydrogen ions from the acid gain electrons and are reduced

25
Q

What happens when a acid reacts with a base

A

A neutralisation reaction occurs

26
Q

Whta is produced in a reaction between an acid and a base

A

A salt and water

27
Q

What do the sum of the charges on the ions in a salt add up to

A

Zero, this enables you to work out the formula of salts, knowing the charges on the ions present

28
Q

How can a pure, dry sample of the salt made in a acid-base reaction canbe crytalised out of a solution

A

By evaporating off most of the water, and drying with filter papers if necessary

29
Q

What is needed when a soluble salt is prepared by reacting an alkali with an acid

A

An indicator, the experiment can then be repeated without the indicator to make a salt, then a pure, dry sample of its crystals prepared

30
Q

What is produced when a carbonate reacts with an acid

A

Produce a salt, water, and carbon dioxide gas

31
Q

How can you test for hydrogen

A

Squeaky pop test (lighted splint)

32
Q

How can you test for carbon dioxide

A

Turns lime water cloudy

33
Q

What do acids produce in aqueous solutions

A

Hydrogen ions (H+)

34
Q

What do aqueous solutions of alkalis contain

A

Hydroxide ions (OH-)

35
Q

What are bases

A

Substances that will neutralise acids

36
Q

What is an alkali

A

A soluble hydroxide

Alkali produce OH- (aq) ions when you add them to water

37
Q

What can the pH scale be used for

A

To show how acidic or alkaline a solution is

38
Q

What are solutions that have a pH value of:
Less than 7
More than 7
7

A

Less than 7 - aicidc
More than 7 - alkaline
7 - neutral solution

39
Q

In neutralisation reaction between an acid and an alkali, how is water produced

A

Hydrogen ions react with hydroxide ions

H+(aq) + OH-(aq) -> H^2O(l)

40
Q

How can you use the universal indictator

A

To find the pH of a solution. It is special indictor made from a number of dyes. It turns a range of colours as the pH changes.

41
Q

What happens to a strong acid (e.g hydrochloric acid) in a aqueous solution

A

Completely ionised

42
Q

What happens to a weak acid (e.g ethanoic acid) in a aqueous solution

A

Partially ionised

43
Q

For a given concentration of aqueous solutions, the stronger an acid….

A

The lower the pH

44
Q

What happens when the pH decreases by one unit

A

The hydrogen ion concentration of the solution increases by a factor of 10

45
Q

Why are some acids described as weak (e.g prpanoic acid), whilst other are described as strong (e.g nitric acid)

A

Nitric acid is a strong acid because it will completely ionise in solution. This means it will split into positive H+ and negative H- ions. While, propanoic acid don’t release H+ ions into the solution.

46
Q

Why is it possible to have very dilute solution of a strong acid with a higher pH value than a concentrated solution of a weak acid

A

This because the strong acid splits up into positive and negative hydrogen ions. While, the weak acids don’t split up. It is reversable with a weak acid