L13. Smells Lesson Outcomes APP AF4 HSW 1c,2c,3a,3c How I did Targets Task 1: Recognise that some cosmetics are made from natural sources. Grade C Task 2:Understand that some cosmetics are synthetic and describe how an alcohol and acid can be reacted to make an ester for use in perfumes. Grade B Task 3: Recall that perfumes have a pleasant smell and describe or explain the other properties they need. Explain their volatility in terms of kinetic theory. Grade A/A* Connector: Explain how emulsifiers work
Transcript
L13. Smells
Lesson OutcomesAPP AF4
HSW 1c,2c,3a,3c
How I did Targets
Task 1: Recognise that some cosmetics are made from natural sources.
Grade C
Task 2:Understand that some cosmetics are synthetic and describe how an alcohol and acid can be reacted to make an ester for use in perfumes.
Grade B
Task 3: Recall that perfumes have a pleasant smell and describe or explain the other properties they need.Explain their volatility in terms of kinetic theory.
• How is this lesson relevant to every day life? (WRL/CIT)
SmellsSmells
•Air freshener.•Soap.•Shampoo.•Washing up liquid.•Moisturiser.
• Name 5 things that have perfume added to them.
New Information for Task 1
• Cosmetics substances used to change a persons appearance or smell for the better
• Cosmetics may be artificial or synthetic
• For example: skin creams may contain polyethylene glycol rather than plant oils or glycerine
What do you think the first cosmetics and perfumes were made of?
•Plants•Flowers•Ground up rocks
Do we still use these today?
Now lots of our cosmetics andperfumes are ‘synthetic’ – meaning human made. i.e. Not natural anymore.
Task 1 (Grade C)
• Task 1:• Name two natural sources of
perfume
Task 1: Review
Lesson Outcomes How I did Targets
Task 1:
Grade C
Met?
Partly met?
Not met?
How can I improve on task 1?
Go back to your lesson outcome grid and fill out the ‘How I did’ and the ‘Targets’ column.
New Information for Task 2
• Perfumes are substances with pleasant smells.
• Perfumes need certain properties to allow them to work properly.
• Q: what are these properties and why is each property important for a perfume?
• Explain why a perfume should not react with water or dissolve in it.
Perfume properties
• For a perfume to be good it needs to have a few important properties:
oEvaporate easilyoNon toxicoDoes not react with water (sweat)oDoes not irritate skinoInsoluble water.
Task 2: Review
Lesson Outcomes How I did Targets
Task 2:
Grade B
Met?
Partly met?
Not met?
How can I improve on task 2?
Go back to your lesson outcome grid and fill out the ‘How I did’ and the ‘Targets’ column.
They evaporate and go into our nose – there they stimulate sense cells that send messages to the brain.
How do we smell perfumes?
How do they evaporate?
Perfumes are made of alcohols. Many alcohols evaporate much quicker than water. The heat from our skin or from thesurrounding environment can make the alcohol evaporate, taking the perfumes smell with it.
New Information for Task 3Volatility: is a measure of how easily a liquid evaporates
• Molecules in liquid are attracted to each other• They must overcome these forces to evaporate • Molecules with lots of energy can do this• Perfumes evaporate easily and attractions between molecules are weak and easily overcome
5. Explain in terms of particles, why a perfume may smell stronger once applied to the skin.
Keywords for Task 3:
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Task 3: Review
Lesson Outcomes How I did Targets
Task 3:
Grade A/A*
Met?
Partly met?
Not met?
How can I improve on task 3?
Go back to your lesson outcome grid and fill out the ‘How I did’ and the ‘Targets’ column.
Review of lesson
• True or false activity
Homework
• Homework task:
• Due date:
• Criteria for Grade C:
• Criteria for Grade B:
• Criteria for Grade A/A*:
Technicians’ List
Bunsen burner, mat, tripod and gauze • test tube rack • test tube containing 1 drop of concentrated sulfuric acid • test tube holder • 250 cm3 beaker •
