ADA - KS3.
Knowledge series |Chemistry | Acids and alkalis | Kevin Brace
Abraham Darby Academy
KS3 Chemistry | Acid/alkali
Knowledge series | Study Booklet | 2017
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ADA - KS3. Knowledge series |Chemistry | Acids and alkalis | Kevin Brace
Key terms
Acid: A substance with particular chemical properties including turning
litmus red, neutralizing alkalis, and dissolving some metals.
Alkali: A substance with particular chemical properties including turning
litmus blue and neutralizing or effervescing with acids.
Base: A substance that will neutralise an acid, but does not dissolve in
water.
pH value: A measure of acidity or alkalinity of water soluble substances
(pH stands for 'potential of Hydrogen').
Atom: The smallest particle of a chemical element that can exist.
Element: Each of more than one hundred substances that cannot be
chemically interconverted or broken down into simpler substances and
are primary constituents of matter.
Compound: A thing that is composed of two or more separate elements;
a mixture.
Endothermic reaction: A chemical reaction that is accompanied by the
absorption of heat
Exothermic reaction: A chemical reaction that is accompanied by the
release of heat
Mixture; A mixture is made from different substances that are not
chemically joined.
Nucleus: The positively charged central core of an atom, consisting of
protons and neutrons and containing the vast majority of mass.
Electron: A subatomic particle with a charge of negative electricity,
found in all atoms and acting as the primary carrier of electricity in solids.
Oxidation: The gain of oxygen by a substance. For example, magnesium
is oxidised when it reacts with oxygen to form magnesium oxide:
magnesium + oxygen → magnesium oxide. 2Mg + O2→ 2MgO.
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ADA - KS3. Knowledge series |Chemistry | Acids and alkalis | Kevin Brace
Task: Tick whether the substances listed in the table below are acid or alkali. In the far right
hand column add a substance which could neutralise it.
Substance Acid Alkali Neutralise
Vinegar
Orange juice
Urine
Ammonia
solution
Garden Lime
Indigestion
powder
Caustic soda
Black coffee
Distilled Water
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ADA - KS3. Knowledge series |Chemistry | Acids and alkalis | Kevin Brace
Task: Fill up the pH scale below with examples of acid and alkalis (bases) – in the right
column. In the left column, list common properties of these acids and alkalis (bases).
Properties Examples
Alkali
7.0
Acid
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ADA - KS3. Knowledge series |Chemistry | Acids and alkalis | Kevin Brace
Task: Fill in the gaps in each of the sentences below.
All substances are divided into three categories:
acids, alkalis and ________________ substances.
There are strong and weak acids and bases, and their
strengths are described by the
________ scale.
Acids typically taste ____________, and will turn litmus
paper _________.
Bases (alkalis) typically taste ____________, and will
turn litmus paper
____________.
pH value is a number from ______ to ________, with ________ as the middle
(neutral) point.
Values below 7 on the pH scale indicate __________ which increases as the number
__________, with 1 being the most __________.
The letters pH stand for ________________ of ___________________
Pure water is neutral, at pH __________, being neither an _________ nor a
____________
Litmus is a water-soluble mixture of different _________. It is often absorbed onto
filter paper to produce one of the oldest forms of pH ___________, used to test
materials (i.e. soil) for acidity.
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ADA - KS3. Knowledge series |Chemistry | Acids and alkalis | Kevin Brace
Task: Fill in the correct colour for the respective pH values in the table below.
pH range Description Colour
<3 Strong acid
3–6 Weak acid
7.0 Neutral
8–11 Weak base
> 11 Strong base
Task: Fill in the blank spaces in the statement below:
The colours from yellow to red indicate an ___________ solution, colours light blue
to dark blue indicate ____________ and green colour indicates that a solution is
______________.
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ADA - KS3. Knowledge series |Chemistry | Acids and alkalis | Kevin Brace
Task: Revise your knowledge of the acid and alkali key terms, by answering the nine
questions below. Underline the correct answer for each question.
1. What is a chemical with a pH less than 7.0 called?
acid alkali (base) neutral compound
2. What is a chemical with a pH of 7.0 called?
acid alkali (base) neutral compound
3. What shows whether something is alkali or acid?
element indicator neutral compound
4. What is a liquid with a solid dissolved in it called?
solution soluble statin stem cell
5. What is the correct terminology when substances chemically combine?
a solution a mixture a reaction an explosion
6. What is a dangerous substance that dissolves other materials called?
a dissolved solution a strong alkali corrosive acid bath
7. What is a corrosive alkali is called?
dangerous caustic corrosive bleacher
8. Name a red and blue indicator
blotter lampit paper litmus paper tinnitus
9. What is the most common solvent called?
A solution neutral solution inert gas water
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ADA - KS3. Knowledge series |Chemistry | Acids and alkalis | Kevin Brace
NOTE: Acids and alkalis can be neutralised, by mixing (chemically) opposite compounds. An
example of this is where farmers mix lime into soil to alter the pH balance. Another
example is the use of antacid tablets to help resolve stomach pain/upsets.
Task: List the process and name the typical chemicals involved that can occur to give us
stomach pains – in boxes 1 and 2. Explain how the antacid tablets can help defeat the pain
in box 3.
1)
2)
3)
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ADA - KS3. Knowledge series |Chemistry | Acids and alkalis | Kevin Brace
Task: Answer the seven questions below.
1. Describe how the pH scale is related to how acidic or alkaline a solution is.
2. Give the name of a compound that contains two elements joined together.
3. Calculate the answer to the following question. Underline your answer.
A chemist burns 0.8 g of iron in oxygen. The iron reacts to form 1.1 g of iron
oxide. Calculate the mass of oxygen that reacted with the iron.
1.9g 1.7 g 1.8 g 0.3 g
4. Copper is used to make electrical wires. Give two properties of copper that
allow it to be used effectively for electrical wires.
Property 1 ________________________________________________________
Property 2 ________________________________________________________
5. Why don’t we use wood to make electronic equipment?
6. Imagine a substance that is a red, shiny solid at room temperature, with a
melting point of 115 °C. It is brittle and a poor conductor of heat. State
whether this substance is a metal or a non-metal. Give a reason for your
answer.
7. This model represents ethane. Write the formula for ethane.
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ADA - KS3. Knowledge series |Chemistry | Acids and alkalis | Kevin Brace
Task: Locate the following words on the word search grid below.
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ADA - KS3. Knowledge series |Chemistry | Acids and alkalis | Kevin Brace
Task: Read the following scenario then answer all three questions.
Scene: James completes an experiment testing the pH of different acids in the lab’.
Q1. Underline his control variables (what he should keep the same) from the list below:
1. Volume of acid
2. Volume of alkali
3. Number of drops of indicator
4. Type of indicator
5. pH of acid
Q2. Identify the independent, dependent and control variables for the above experiment.
Independent
Dependent
Control
Q3. Explain why understanding variables are so important in experiments like this.
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ADA - KS3. Knowledge series |Chemistry | Acids and alkalis | Kevin Brace
Task: Describe what the diagram below shows. State the names of the chemical
reactions taking place in the diagram
1
2
3
4
5
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ADA - KS3. Knowledge series |Chemistry | Acids and alkalis | Kevin Brace
Task: Answer the three questions below
Q1. Give an example of a precaution (a safety measure) you take when using an alkali.
Q2. Describe what to do to treat an alkaline wasp sting and help to
neutralise the effect?
Q3. Study the graph below. State what the lab’ assistant changed in this experiment? What
would be a suitable conclusion for the experiment? Add a suitable title for the graph.
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ADA - KS3. Knowledge series |Chemistry | Acids and alkalis | Kevin Brace
Tasks: 1) State when and why a farmer would add alkali to his soil? 2) What would be a
suitable alkali for this purpose? 3) Explain how a farmer would test the pH of his soil.
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ADA - KS3. Knowledge series |Chemistry | Acids and alkalis | Kevin Brace
Task: Answer the following five questions.
Q1. Write a word equation for neutralisation using these substances.
Water, Sodium hydroxide, Sodium Chloride, Hydrochloric acid
Q2. Underline a reactant in this word equation:
Nitric acid + Potassium Hydroxide + Potassium Nitrate + Water
Q3. Fill in in the blanks of the following sentence.
Salts are made by the _________ of acids with ____________.
Q4. Underline the correct measurement for volume.
cm3 , cm2, cm
Q5. If this glass beaker was 10cm diameter, and 50 cm tall; how much liquid can it contain?
clue:
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ADA - KS3. Knowledge series |Chemistry | Acids and alkalis | Kevin Brace
Task: You will design an experiment to compare three different acids. You need to find out
which is the most hazardous, by observing and recording how well they react. Include all safety
wear, safety precautions, and apparatus needed.
Apparatus list
Reactants/chemicals list
Method
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ADA - KS3. Knowledge series |Chemistry | Acids and alkalis | Kevin Brace
Task: What is the common link with the above food/drink items?
Task: fill in the blanks to each statement below:
Acids have a ____________ taste
Vinegar contains ____________ acid
Lemons contain __________ acid
Fizzy drinks contain ____________ acid
Tea contains ___________ acid
Vitamin C is also called ________ acid, found in fruit and
vegetables.
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ADA - KS3. Knowledge series |Chemistry | Acids and alkalis | Kevin Brace
Task: Use the clues at the bottom of the page to complete this crossword.
Across DOWN
1. Burning something in air. (10)
4. Chemical reaction with oxygen. (9) 1. To react metal with the atmosphere and water.
6. Produce palatable food by applying heat. (4) (7)
8. Atom with an excess + or – electric charge. 2. A chemical building block used to form plastics.
(3) (7)
9. A tiny particle, much lighter than an atom, 3. A technique used to separate liquids with
that different boiling points. (12)
carries a negative electric charge. (8) 5. A negative ion that travels towards the positive
15. Fossil fuel raw material used to make most anode. (5)
plastics.(3) 7. Fuel used in aircraft, also called kerosene.(8)
16. A fraction of crude oil that is used in buses 10. A substance that increases the rate of a
and chemical reaction but that is not used up itself. (8)
lorries as a fuel. (6) 11. Breaking long chain hydrocarbon molecules
17. A positive ion that travels towards the into more useful short chain molecules. (8)
negative 12. General name for a polymer like polythene,
cathode. (6) polypropylene, nylon and polystyrene. (7)
18. Where new chemical products form from 13. A portion of crude oil with a particular boiling
chemical reactants. (8) point. (8)
14. A very long molecule formed from a string of
identical chemical building blocks. Often a type of
plastic. (7)
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ADA - KS3. Knowledge series |Chemistry | Acids and alkalis | Kevin Brace
Task: Revise your knowledge of the acid and alkali key terms, by answering the sixteen
questions below. Write the correct answer for each question.
1. What is the chemical formula for sodium hydroxide?
2. A substance with a pH of 3 would be?
3. Give one example of a substance that is acidic.
4. Universal indicator turns ___________ in presence of an acid
5. Give two examples of substances that are alkali.
6. What is the name of the compound with the formula CuO?
7. The formula of sulfuric acid is?
8. HNO3 is the formula for which acid?
9. Complete the word equation: Acid + metal carbonate →
10.What is formed in a neutralisation reaction?
11.CaCO3 is the formula for what?
12.What is the name of the salt that is made from sulphuric acid?
13.Acids have a pH of?
14. Acid rain is caused by which pollutant gases?
15. What can farmers put onto the soil to change the pH levels?
16.What does the pH scale indicate?
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ADA - KS3. Knowledge series |Chemistry | Acids and alkalis | Kevin Brace
NOTES
Image attribution
Most images are sourced from Wikimedia. These are shared under the Creative Commons Attribution-Share Alike 4.0
International license. Other images are sourced from online repositories, i.e. Pixabay. Those are released and shared under
CC0 Public Domain (i.e. freely reusable, and no attribution required).
Booklet released and shared under Attribution-NonCommercial-ShareAlike 2.0
Generic (CC BY-NC-SA 2.0)
https://creativecommons.org/licenses/by-nc-sa/2.0/
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