KS3 ScienceReactions 1 Home

Learning

Name : _____________________________________Class : ______________________________________

Teacher : ___________________________________

In this topic you will learn about:• Reactions of metals • Acids• Alkalis

Practical Skills: • Exploring neutralisation reactions• GCSE RP– making Epsom salts

This will prepare you for:• GCSE chemistry topic ‘Chemical Changes’

This topic has links to• Matter, Chemical changes, particle model

Maths in science: • Analysing patterns • Plotting Graphs• Rearranging equations

1

Booklet expectations:

The booklet is your responsibility to look after and keep tidy.

You are expected to bring the booklet to every lesson with that class teacher.

Any corrections / self assessment to be completed in green pen, as indicated by your class teacher – Or when you see the ‘feedback & assessment’ logo

Any response to marking and literacy codes to be completed in green pen.

Any diagrams are to be drawn in pencil, graphs using a pencil and ruler etc.

All activities are to be completed, including homework, to the best of your ability, and corrected where needed.

When reading through the notes, you are expected to highlight any words you do not understand, then write their definitions on the glossary pages at the back of the booklet.

Contents: Page no:

3

7

11

15

19

26

30

35

38

43

46

47

Lesson 1: Using metals and non-metals

Lesson 2: Reactions of metals with acids

Lesson 3: Displacement reactions

Lesson 4: Oxidation reactions

Lesson 7: Acids

Lesson 8: Alkalis

Lesson 9: Indicators

Lesson 10: Exploring neutralisation

Lesson11: Investigating neutralisation

Lesson 12: Revision

Glossary

Answers

2

Week commencing 25th Jan – 15th March2 lessons per week

Lesson 1: Using Metals and Non-MetalsIn and On: What do you know about…Metals;

Non-Metals;

Most elements are metals, rather than non-metals. Some metals have similar properties, such as being strong and shiny. These properties help us in different uses. Non-metals are neither strong nor shiny, and some are gases are room temperature.

Metals

Task 1: What are the properties of metals?

3

4

Non -

Metals

What are the properties of non-metals?

Challenge: Describe what is unusual about bromine. Suggest why it is used in swimming pools.___________________________________________________________________________________________________________________________________________________________________________

5

Metals and their AlloysIron is a strong, grey metal which makes it useful as a structural material. Copper is an orange-coloured metal that is more malleable and ductile than iron. It is used in electrical circuits, wires and water pipes. Copper does not corrode. Iron, cobalt and nickel are usual because they are the only magnetic metals. Other metals have usual properties, for example, mercury is a liquid at room temperature.

Task 3 : For each of the diagrams below write down if the element is a metal or a non- metal.

Iron is a ___________.

Bromine is a ____________.

Copper is a ___________.

M_________ is the only metal that is a liquid at room temperature.The ____________ metals are iron, cobalt and nickel.____________ can be hammered into shape.

6

Task 4: What is an alloy and why are alloys often used instead of pure metals? Give an example of an alloy.______________________________________________________________________________________________________________________________________________________________________________

Additional Notes: _________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

7

Lesson 2 – Reactions of Metal with Acid

In and On: Which cup contains an acid?Which cup contains an alkali?Which cup contains an a neutral substance?

List as many metals as possible. Extension: Can you add the uses _____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

8

9

When a metal reacts with an acid a salt and hydrogen gas is produced. The name of the salt depends on the acid. The general word equation is:

metal + acid → salt + hydrogen

The type of salt produced depends on the type of acid and metal used. For example, magnesium reacts with hydrochloric acid to produce magnesium chloride: magnesium + hydrochloric acid → magnesium chloride + hydrogen

Task 4:

Watch the video https://www.youtube.com/watch?v=t5srg32crLY

Write down your observations of magnesium with hydrochloric acid;

_______________________________________________________________________________________________________________________________________________________________

How do we test for hydrogen gas? _______________________________________________________________________________________________________________________________________________________________

Acid Second reactant Name of salt + Gas

sulfuric magnesiumM______ S______ + H________

sulfuric calcium______ ________+_____

nitric zinc______ ______ + ________

nitric magnesium________ ______ +_________

hydrochloric iron_____ _______ + ________

hydrochloric zinc_____ _______ + ________

sulfuric lead______ ______ +_________

Acid Name of salt

Hydrochloric Chloride

Sulfuric Sulphate

Nitric Nitrate

The type of salt produced depends on the type of acid and the metal used. The table shows the acids and the names of salt produced.

Challenge: Suggest why it is unsafe to collect too much hydrogen gas before testing it. __________________________________________________________________________________________________________

Lesson 3: Displacement Reactions In and On: Why do some people have gold fillings?

Why not a cheaper metal such as iron?

Learning Outcomes:Successfully conduct an experiment Create a reactivity series from experimental resultsEvaluate whether a reaction will occur using the reactivity series

Reactivity Series: Some metals are very unreactive. This means they do not easily take part in chemical reactions. For example, platinum does not react with oxygen in the air, even if it is heated in a Bunsen burner flame.Some metals are very reactive. They easily take part in chemical reactions to make new substances.

Other metals may be more reactive than magnesium, or in between magnesium and platinum. If we put the metals in order of their reactivity, from the most reactive down to the least reactive, we get a list called the reactivity series.

11

Displacement Reactions

12

Task 1:

13

Task 2: Watch the videohttps://www.youtube.com/watch?v=Zh3f4-NBuVk

Put a ✓ in your results table if a reaction happened, or a if a reaction did not happen.

MagnesiumSulphate

ZincSulphate

Iron SulphateCopper

Sulphate

Magnesium

Zinc

Iron

Copper

Challenge: Can you write the word equations for the reactions that took place. ______________________________________________________________________

__________________________________________________________________________________________________________________________________________________________________________________________________________________

Task 3: Use your results to construct a mini reactivity series for the 4 metals you used.

14

Lesson 4 – Oxidation Reactions

1. What is the general word equation:

_____________________________________________________________________________________________________________

15

When a metal reacts with oxygen there is a chemical change and a metal oxide is produced.

2. What is an oxidation reaction?

______________________________________________________________________________________________________________

3. Give 3 everyday examples of oxidation reactions.________________________________________________________________________________________________________________

16

17

When metals and oxygen react, they form metal oxides.

Metal + Oxygen →Metal oxide

The type of metal oxide formed depends on the metal.

Match the type of metal formed to the oxide it forms.

Iron

Copper

Zinc

Iron oxide

Zinc oxide

Copper oxide

Using what you know, complete the word equations for these reactions:

1. Magnesium + Oxygen →M______________ O_________

2. Sodium + Oxygen → _____________________________

3. Calcium + Oxygen → _____________________________

4. Titanium + Oxygen → ____________________________

5. Nickel + Oxygen → ______________________________

Additional Notes: _________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Acids, bases, alkalis and metals are found in the laboratory and at home. They

can be irritant or corrosive and must be handled carefully.

Acids and Bases

Many foods and drinks contain weak acids. They give a sour and tangy taste.

Dilute acids are irritant

This means that if any of them make contact with your skin, it will become red or

blistered.

You must wash off any spills with plenty of water, otherwise your skin will soon feel as if

it is burning.

Concentrated acids are corrosive

You are unlikely to have used concentrated acids.

This is because concentrated acids are corrosive. They can attack metals and

destroy skin if spilled.

Lesson 5 - Acids

19

Lesson 5 - Acids

In & On: List as many hazards in the lab as you can

_____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

20

• Understand what an acid is.• Identify the hazards that acids pose.• Explain the difference between a dilute acid and a concentrated one.

1. What do all acids have in common?______________________________________________________________________________________________________________________________________

Vinegar

Lemons

Oranges

Tea

Fizzy drinks

Vitamin C

Carbonic acid

Citric Acid

Ethanoic Acid

Tannic Acid

Match the acid to the food that contains it;

Challenge: Can you think of any examples of acids and alkalis in the home

Practical: How does the concentration of acid affect the energy change in a reaction between hydrochloric acid and magnesium?

Method

1. Measure out 5cm3 of acid and pour into a test tube

2. Record the temperature of the acid

3. Add magnesium strip. Record the maximum temperature of the reaction

4. Record your results and observations

5. Repeat for other acid samples

On the graph paper, plot a bar chart of the students results

Conclusion: Describe your results________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

22

Concentration of

acid (M)

Starting

temperature (⁰C)

Finishing temperature (⁰C)

Temperature change (⁰C)

0.1 18 20

0.5 19 26

1.0 18 34

Graph (Concentration(x axis) vs temperature

change (y-axis))

23

24

2. Why are concentrated acids more dangerous then dilute acids?____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

3. What is the difference between a dilute acid and a more concentrated one? (Look at the particles in the diagram above). ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

25

Lesson 6 – Alkalis

In & On: Complete the following

What is an alkali? ________________________________________________________________________________________________________________________________________________________________________________________

26

What is an alkali?

A base is a compound that can neutralise an acid.

An alkali is a soluble base which is very corrosive.

Alkali solutions turn pink litmus paper blue.

1. What is the common feature of all alkalis?

____________________________________________________________________________________________________________________________________________________________________________________________________________________________________

27

2. Name some alkaline cleaning products.

3. Name two alkaline substances that are safe to put in your mouth

and two that are not.

_______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Questions

Additional notes:________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Key Vocab:

28

30

Lesson 7 – Indicators

1. What is an indicator?_____________________________________________________________________________________________________________________________________________________________________________________________________________________

2. Describe the colour change of litmus paper in an acid and in an alkali._____________________________________________________________________________________________________________________________________________________________________________________________________________________

https://www.youtube.com/watch?v=ckbsHM2igT0

Learning Outcomes:Describe the pH scale.Use experimental results to decide is a substance as acidic, neutral or alkaline.Explain the advantage of universal indicator in comparison with litmus paper.

31

When an acid is dissolved in water we get an acidic solution, and bases

make alkaline solutions. If a solution is neither acidic nor alkaline we call it

neutral. Pure water is neutral, and so is paraffin.

Indicators are substances that change colour when they are added to acidic or

alkaline solutions. You can prepare homemade indicators from red cabbage or

beetroot juice - these will help you see if a solution is acidic or alkaline.

32

Word bankLitmus Orange Hydrochloric acid NeutralisationVinegar Washing soda Alkaline Indicator

Indigestion Sodium hydroxide ReactionUniversal indicator Acidity Toothpaste

The pH number gives an indication of the strength of an acid or alkali. Strongly acidic substances, such as ……………………………………………, are pH 1 and will turn universal indicator red. Ethanoic acid, commonly known as ……………………………………………, is pH 3. Weaker acids (pH 4), such as those found in some fruits, will turn universal indicator …………………………………………….

Water is neutral (pH 7) and will turn universal indicator green.

Weak alkalis (pH 8), such as ……………………………………………, will turn universal indicator dark green/blue. Strongly …………………………………………… substances, for example ……………………………………………. and ……………………………………………, have a pH of 12-14 and will turn universal indicator purple.

The …………………………………………… between an acid and an alkali is called …………………………………………… . The products are salt and water. A weak alkali in tablet or powder form is used to treat ……………………………………………, which is caused by excess acid production in the stomach often, from overeating.

Complete the missing gaps using the word bank below.

Indicators

How do you know whether a substance is an acid or an alkali?

33

Complete the table below by adding the colour or pH number:

Answer the following

34

Lesson 8 Neutralisation

In & On: What do you think happens when we mix an acid and an alkali?

Learning Outcomes:Describe how to make a neutral solution.

Describe a neutralisation reaction using a simple word equation.

Explain how we useneutralisation reactions in everyday life.

Word Equation:

REACTANTS PROCUCTS pH7Acid + Alkali → Salt + Water

https://www.youtube.com/watch?v=_cB2vSaalXg

https://www.youtube.com/watch?v=-fyev2aWcLs

36

Research - Find some examples of useful neutralisation reactions, share your findings as an information poster.

Research Useful neutralisation reactions.

37

38

Some people experience heartburn when they eat certain foods.This is caused by acid in the persons stomach.

How could you treat heartburn?

Antacids are bases which can be ingested to reduce the symptoms of heartburn.

Lesson 9 – Investigating Neutralisation

Learning Outcomes:Describe what is meant be an antacid. Explain how the use of an antacid involves a neutralisation reaction.Evaluate the effectiveness of different antacids.

38

What is an antacid?

Hypothesis: I predict that …………………. will reduced the pH of the hydrochloric acid the fastest because ………

Antacid Time taken to neutralise the acid/ s

Rennie 220

Gaviscon 65

Sainsbury's 340

Tesco 280

Asda 210

Conclusion: The antacid tablet that was the best at neutralising the acid was_____________________________ because………___________________________________________________________________________________________________________________________________________________________________________________________________________________________

39

Results:

You are going to investigate which antacid in the selection providedis the most effective at neutralising hydrochloric acid. Measure out100cm3 of hydrochloric acid into a beaker and add universal indicator.Then add your crushed antacid tablet and start the stop clock. As soon as the universal indicator shows a neutral pH stop the stop clock.

On the graph paper, plot a bar chart of the students results

40

41

42

Lesson 10 Revision –Acids and Alkalis

• Watch this video: https://www.youtube.com/watch?v=Hzk2nU7uBw4

Whilst watching answer the questions given below.

43

45

REVISION SUMMARY

46Glossary

Key term DefinitionAntacid A substance that neutralises stomach

acid.

Base A substance that neutralises an acid

Neutralisation When an acid and base react to form a

neutral substance.

Indicator A chemical which changes colour when

placed in an acid and an alkali

Neutral When a substance is neither acidic or

alkaline

pH Measure of acidity/alkalinity on a scale

from 0-14

Alkali A soluble substance with a pH higher than

7

Hydroxide A Particle present in all alkalis

Acid A substance that has a lower pH than 7

Corrosive Reacts with materials and makes them

dissolve

Concentration The number of particles in a certain

volume of substance

Reactivity The tendency of a substance to undergo

a chemical reaction

Oxidation Chemical reaction in which a substance

combines with oxygen

Combustion A reaction with oxygen which releases

heat and light to the surroundings

Displacement A reaction in which a more reactive

metal replaces a less reactive metal

Salt Type of chemical compound- our table

salt is sodium chloride 29

Answers:Lesson 1 Task 1:

47

Shiny

Flexible-ductile and malleable

Good heat conductors

Solids at room temperature

Good electrical conductors

Strong

Metals

Often gases/liquids or solids that melt easily

Good electrical insulators

Good heat insulators

Dull

BrittleNon -Metals

Challenge: Describe what is unusual about bromine. Suggest why it is used in swimming pools.Bromine is unusual because it is a liquid at room temperature. It can be used to treat swimming pool water and pesticides.

Task 3: Iron is Metal. Bromine is Non-Metal. Copper is Metal.

Mercury is the only metal that is a liquid at room temperature.The magnetic metals are iron, cobalt and nickel.Metals can be hammered into shape.

Task 4: What is an alloy and why are alloys often used instead of pure metals? Metals can be mixed together to form alloys. Alloys are sometimes more useful than pure metals and the properties change.

What is an alloy of iron? Stainless steel

Lesson 2:

Task 4: How do we test for hydrogen gas?

You can test for hydrogen gas because it burns with a pop. Place a lit splint into the top of a test tube in which a acid and a metal are reacting and you will hear a ‘pop’ sound.

Challenge: A large amount of hydrogen would be highly explosive, and therefore dangerous to ignite.

48

AcidSecond reactant

Name of salt + Gas

sulfuric magnesium Magnesium Sulphate + Hydrogen

sulfuric calciumCalcium Sulphate + Hydrogen

nitric zinc Zinc Nitrate + Hydrogen

nitric magnesiumMagnesium Nitrate + Hydrogen

hydrochloric iron Iron Chloride + Hydrogen

hydrochloric zinc Zinc Chloride + Hydrogen

sulfuric lead Lead Sulphate + Hydrogen

49

Lesson 3: Task 1:

No reaction

reaction

reaction

No reaction

Magnesium

Sulphate

Zinc

SulphateIron Sulphate

Copper

Sulphate

Magnesium

Zinc

Iron

Copper

Challenge: magnesium + zinc sulphate magnesium sulphate + zincmagnesium + iron sulphate magnesium sulphate + ironmagnesium + copper sulphate magnesium sulphate + copperZinc + Iron sulphate Zinc sulphate + IronZinc + Copper sulphate Zinc sulphate + CopperIron + Copper sulphate Iron sulphate + Copper

50

Task 3: Use your results to construct a mini reactivity series for the 4 metalsyou used

Increasing Reactivity

Magnesium

Zinc

Iron

Copper

Lesson 4: 1. General Equation

Metal + Oxygen → Metal Oxide

2.3.

There is a colour change, heat/light given out, new substance formed, irreversible

Oxides

Cu + O O → Cu O

Mg+ O O → Mg O

Copper + Oxygen → Copper Oxide

Magnesium + Oxygen → Magnesium Oxide

52

Cu + O2 → CuO

Mg + O2 → MgO

Zn + O2 → ZnO• Ca + O2 → CaO

Iron

Copper

Zinc

Iron oxide

Zinc oxide

Copper oxide

Using what you know, complete the word equations for these reactions:

1. Magnesium + Oxygen →Magnesuim Oxide

2. Sodium + Oxygen → Soduim Oxide

3. Calcium + Oxygen → Calcuim Oxide

4. Titanium + Oxygen → Titanium Oxide

5. Nickel + Oxygen → Nickel Oxide

53

AnswersLesson 5

1

1

1

2

2

2

3

4

5

6

5 5

6

6

44

3

3

2. Why are concentrated acids more dangerous then dilute acids?

They are corrosive (destroy skin, attack metals).

1.What do all acids have in common?They contain hydrogen.

3.What is the difference between a dilute acid and a more concentrated one?

For the same volume a concentrated acid has more acid particlesthan a dilute acid.

54

Lesson 7

Worksheet: 2 What are the risks 3. Identifying elements

Questions

1. Bleach; oven cleaner; soap; disinfectant; washing powder.2. Safe – toothpaste and baking powder; not safe – bleach and

oven cleaner.3. They contain hydroxide ‘particles’.

What is an alkali?

A base is a compound that can neutralise an acid. An alkali is a soluble base

v

Lesson 6

56

What is an indicator?1. An indicator is a substance that has different colours when in an acid and in an alkali.

Describe the colour change of litmus paper in an acid and in an alkali.2. Red in acid; blue in alkali.

Lesson 7

The acidity or alkalinity of a substance can be shown using an indicator. Litmus and universal indicator are common examples of these substances.

The pH number gives an indication of the strength of an acid or alkali. Strongly acidic substances, such as hydrochloric acid, are pH 1 and will turn universal indicator red. Ethanoic acid, commonly known as vinegar, is pH 3. Weaker acids (pH 4), such as those found in some fruits, will turn universal indicator orange.

Water is neutral (pH 7) and will turn universal indicator green.

Weak alkalis (pH 8), such as toothpaste, will turn universal indicator dark green/blue. Strongly alkaline substances, for example sodium hydroxide and washing soda, have a pH of 12-14 and will turn universal indicator purple.

The reaction between an acid and an alkali is called neutralisation. The products are salt and water. A weak alkali in tablet or powder form is used to treat indigestion, which is caused by excess acid production in the stomach, often from overeating.

Lesson 81a)

58

Lesson 9

1. CBAD

What is an antacid?

Antacids are bases which can be ingested to reduce the symptoms of heartburn. An antacid neutralises stomach acid.

Lesson 10

59

Lesson 10

60Glossary

Key term DefinitionAntacid A substance that neutralises stomach

acid.

Base A substance that neutralises an acid

Neutralisation When an acid and base react to form a

neutral substance.

Indicator A chemical which changes colour when

placed in an acid and an alkali

Neutral When a substance is neither acidic or

alkaline

pH Measure of acidity/alkalinity on a scale

from 0-14

Alkali A soluble substance with a pH higher than

7

Hydroxide A Particle present in all alkalis

Acid A substance that has a lower pH than 7

Corrosive Reacts with materials and makes them

dissolve

Concentration The number of particles in a certain

volume of substance

Reactivity The tendency of a substance to undergo

a chemical reaction

Oxidation Chemical reaction in which a substance

combines with oxygen

Combustion A reaction with oxygen which releases

heat and light to the surroundings

Displacement A reaction in which a more reactive

metal replaces a less reactive metal

Salt Type of chemical compound- our table

salt is sodium chloride 29