PowerPoint PresentationName: _____________________________ Class: _____________________________ Teacher: ___________________________
In this topic you will learn about: • Exothermic and Endothermic reactions.
• How to represent energy changes in reactions.
• How to speed up reactions.
Practical skills: • Measuring temperature changes
This will prepare you for: • GCSE Chemistry
• GCSE Physics
Contents:
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.
Lesson 1: Exothermic reactions Lesson 2: Endothermic reactions Lesson 3: Investigating endothermic reactions Lesson 4: Catalysts Lesson 5: Exploring combustion Lesson 6: Exploring the use of fuels Lesson 7: Understanding thermal decomposition Lesson 8: Explaining changes Lesson 9: Revision Lesson 10: Test Lesson 11: Green for Growth
Week commencing 8th Feb – 1st March 4 lesson per week
Key term Definition
Lesson 1: Exothermic Reactions
Lesson 1: Exothermic Reactions
In and On: Look at the images on the board. Are the following physical or chemical changes?
1. Ice melting
3. Burning magnesium
Challenge: What is the difference between a physical and chemical change?
Learning Objectives • Describe examples of exothermic reactions • Explain the energy changes taking place during an exothermic
reaction
Challenge: An example of an exothermic reaction is….
Energy changes occur in all ___________ ____________. In exothermic reactions, energy is ________ _____ , usually in the form of ______. This means that the temperature of the surroundings __________.
Record your observations to identify the exothermic reaction
Explain, using ideas about particles and atoms, why burning magnesium is an exothermic reaction. ______________________________________________________ ______________________________________________________ ______________________________________________________ ______________________________________________________
Citric acid and baking soda Magnesium ribbon and Hydrochloric acid
Temperature at start (oC) 23 22
Temperature at end (oC) 10 42
Conclusion:
_____________________________________________________ _____________________________________________________ _____________________________________________________
Citric Acid and Baking soda 1. Add 2cm depth of citric acid to a
test tube 2. Record temperature 3. Add 1 spatula scoop of baking
soda 4. Record temperature
Magnesium ribbon and Hydrochloric acid 1. Add 2cm depth of Hydrochloric
acid to a test tube. 2. Record temperature 3. Add a few pieces od magnesium
ribbon 4. Record temperature
Lesson 2 : Endothermic reactions
Endothermic reactions Energy from the surroundings is transferred to the reacting chemicals, causing the temperature of the surroundings to decrease. Examples include: •Thermal decomposition •The reaction between citric acid and sodium hydrogen carbonate (sodium bicarbonate).
Lesson 2 : Endothermic reactions
In and On: Using only addition, how can you add eight 8's to get the number 1,000?
Learning Outcomes: • Describe examples of endothermic reactions • Explain the energy changes taking place during an
endothermic reaction
What is the difference between endothermic and exothermic reactions? _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________
Practical 1: 1. Fill a test tube 1/3 with
Copper sulfate 2. Record the temperature 3. Add a 2cm length of
magnesium ribbon 4. After 1 minute, record the
temperature. Results: 5 degree temperature
increase
Practical 2: 1. Fill test tube 1/3 water 2. Add 1 spatula of Sodium
Bicarb 3. Record the temperature 4. Add 1 spatula of Citric acid 5. After 1 minute, record the
temperature. Result: 7 degree temperature decreasePractical 1
This reaction was ____________. I know this because…
Practical 2 This reaction was ____________. I know this because…
_________________________________________________ _________________________________________________
_________________________________________________ _________________________________________________
Reaction Start Temp (oC) End Temp (oC) Temp Change (oC) Exo or Endo
A 22.0 33.4
B 18.6 41.7
C 24.3 19.5
D 6.1 21.7
E 22.0 -3.6
F -12.2 2.3
Endothermic reactions In an endothermic reaction, more energy is _____________. Endothermic means to take in _________. This means that in an endothermic reaction, the temperature _____________. The most important endothermic reaction for life is ________________.
1. Which type of reaction gives out energy to the surroundings?
2. Thermal decomposition is an example of …
3. Combustion is an example of…
4. Which type of reaction causes the temp of the surroundings to decrease?
5. An Ice pack is an example of…
Endothermic or Exothermic?
How can you tell this reaction is endothermic? _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________
Lesson 3: Investigating endothermic Reactions In and On: Is this reaction endothermic or exothermic? ________________________________________________________________________
Challenge: How do you know?_______________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________
1. Measure out 10 cm3 of water using a measuring cylinder. Record the starting temperature of the water in your results table
2. Collect a polystyrene cup with a pre weighed amount of potassium chloride in it. Record the mass to the appropriate number of decimal places in the table.
3. Add the water to your cup. Record the lowest temperature shown on your thermometer and record this answer to the appropriate number of decimal places.
4. Calculate the change in temperature.
Method:
Start temperature (oC)
End temperature (oC)
• Remove any anomalous results
• Ensure you have labelled each axis and state the unit
• Ensure gaps are uniform ie. Every square is equal to 2 degrees Celsius
• Draw a line of best (either with a ruler or a curve – do NOT join the points)
Conclusion:
_______________________________________________________________________ _______________________________________________________________________ _______________________________________________________________________ _______________________________________________________________________ _______________________________________________________________________
Challenge: Why did you use a polystyrene cup rather than a beaker? _______________________________________________________________________ _______________________________________________________________________
How could you improve the experiment to make your results more reliable? _______________________________________________________________________ _______________________________________________________________________ _______________________________________________________________________
Additional notes: _________________________________________________ _________________________________________________ _________________________________________________ _________________________________________________ _________________________________________________ _________________________________________________ _________________________________________________ _________________________________________________ _________________________________________________ _________________________________________________ _________________________________________________ _________________________________________________ _________________________________________________ _________________________________________________ _________________________________________________ _________________________________________________
Remember – Particles need to collide with enough energy (activation energy) to react. A catalyst provides an alternative reaction pathway with a lower activation energy, so there are more successful collisions.
Lesson 4: Catalysts In and On: Which road would you choose and why? ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________
Road 1
Road 2
1. What are the 4 factors affecting the rate of reaction?
2. What is the activation energy?
3. What does the rate of a reaction depend on? 1. 2.
4. Why does the rate of reaction increase with increased temperature?
5. Why are catalysts not included in reaction equations?
6. How do catalysts speed up the rate of reaction?
7. Give 2 examples of catalysts
Additional notes: _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________
Learning Objectives:
• To describe what a catalyst is • Explain how catalysts work
Which graph shows a reaction with a catalyst? Explain your answer. _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________
U si
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Reactions 2 Catalysts
Nitrogen + Hydrogen → Ammonia
N2 (g) + 3 H2 (g) → 2 NH3 (g)
An iron catalyst is used to speed up the rate of this reaction.
Making Margarine
This type of reaction is known as hydrogenation.
Example: Ethene + Hydrogen → Ethane
A nickel catalyst is used to speed up the rate of this reaction.
Reactions 2 Catalysts
Reactions 2 Catalysts
A three step reaction. The catalyst is needed in step 2.
Step 1: Sulfur + Oxygen → Sulfur dioxide Step 2: Sulfur Dioxide + Oxygen → Sulfur Trioxide Step 3: Water + Sulfur Trioxide → Sulfuric Acid
A Vanadium Oxide catalyst is used to speed up the rate of this reaction.
Catalytic Converters in Cars They convert harmful emissions into less harmful substances.
Carbon monoxide + Oxygen → Carbon dioxide 2 CO (g) + O2 (g) → 2 CO2 (g)
Carbon monoxide + Nitrogen monoxide → Carbon dioxide + Nitrogen 2 CO (g) + 2 NO (g) → 2CO2 (g) + N2 (g)
Hydrocarbons + Nitrogen monoxide → Carbon dioxide + Nitrogen + Water
Rhodium, Palladium and Platinum can be used as a surface for the catalytic converter.
Reactions 2 Catalysts
Challenge: Write this as a symbol equation:
Lesson 5: Combustion
In and On: match the reaction to its definition
Extension: how are hand warmers an example of an exothermic reaction? ________________________________________________________________________ ________________________________________________________________________
Physical reaction
Physical properties of a substance changes but no new substances are made
Chemical reaction
Exothermic reaction
Endothermic reaction
One or more substances are changed into others by rearranging their atoms
Learning Objectives: • Summarise combustion using an equation • Make observations during chemical reactions • Write word equations to represent chemical equations
Methane + Oxygen → Carbon dioxide + Water
When a fuel burns, chemical energy is transferred into heat ___________. Wood, coal, petrol and gas are all examples of ___________. Burning is a _________ reaction. The scientific name for burning is _______________.
When a fuel burns, it reacts with ____________ in the air to form carbon dioxide and ______________. The reaction also gives out ______________ energy.
CH4 + O2 → CO2 + H2O
Can you light a candle on the moon? Explain your answer. _______________________________________________________________ _______________________________________________________________
Label the reactants and products for the following reaction:
Write this as a symbol equation:
CH4 + O2 → CO2 + H2 O +
What is the difference between complete and incomplete combustion? _______________________________________________________________ _______________________________________________________________
Describe why burning is a chemical reaction _______________________________________________________________ _______________________________________________________________ Explain why a fire will burn more brightly is you fan the flames with air _______________________________________________________________ _______________________________________________________________ Describe the problems associated with the production of carbon dioxide _______________________________________________________________ _______________________________________________________________ Challenge Explain why combustion is also known as an oxidation reaction _______________________________________________________________ _______________________________________________________________
Additional notes: _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________
Lesson 8: Explaining changes
Lesson 8: Explaining changes
In & On: What would be the mass of the salt solution? Explain your answer.
Law of conservation of mass ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________
What is physical change? ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________
Learning Objectives:
• Observe and explain mass changes for chemical and physical processes • Use particle diagrams to explain chemical processes
Mass of water: 250g Mass of salt = 5g
If 6g of calcium reacts with 2g of oxygen, what mass of calcium oxide will form?
If 12g of calcium oxide forms from 9g of calcium, what mass of oxygen has reacted?
Examples: Calcium + Oxygen → Calcium oxide
Magnesium and Magnesium Oxide are both solids at room temperature. Oxygen is a gas. Predict – what would appear to happen to mass when they react? _____________________________________________________________ _____________________________________________________________ _____________________________________________________________
Burning Magnesium
Describe and Explain what appears to happen to mass when magnesium and oxygen react. _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ Challenge: Describe and Explain what appears to happen to mass during the thermal decomposition of copper carbonate. _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________
Total mass of reactants = Total mass of products
If one of the reactants is a gas, mass can appear to ________________
If one of the products is a gas, mass can appear to ________________
10.00g 50.00g
5.00g 9.00g
______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________
______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________
4 K (s) + O2 (g)→ 2 K2O (s)
Additional notes ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________
End of Topic Summary Questions:
•
•
Write out a word equation for the reaction
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C3H8 + O2 → CO2 + H2O
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Revision The next 2 pages are left blank for you to use for revision in preparation for the end of topic test. Your teacher may ask you to complete a specific revision activity or ask you to revise independently. Suggested activities include: Mind maps, practice questions from the text book, flash cards, memorising key words and concepts.
Student book part 2 pages 102-121