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L13. Smells
Lesson Outcomes
How I did
Targets
APP AF4
HSW 1c,2c,3a,3c
Connector:
Task 1: Recognise that some cosmetics are
made from natural sources.
Grade C
Explain how
emulsifiers
work
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*
Using additives
BIG picture
• What skills will you be developing this lesson?
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ICT
Numeracy
Literacy
Team work
Self management
Creative thinking
Independent enquiry
Participation
Reflection
• How is this lesson relevant to every day life?
(WRL/CIT)
Smells
• Name 5 things that have perfume added to
them.
•Air freshener.
•Soap.
•Shampoo.
•Washing up liquid.
•Moisturiser.
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 and
perfumes 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
Go back to your lesson outcome grid and fill out
the ‘How I did’ and the ‘Targets’ column.
Lesson Outcomes
Task 1:
Grade C
How I did
Met?
Partly met?
Not met?
Targets
How can I improve
on task 1?
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 easily
oNon toxic
oDoes not react with water (sweat)
oDoes not irritate skin
oInsoluble water.
Task 2: Review
Go back to your lesson outcome grid and fill out
the ‘How I did’ and the ‘Targets’ column.
Lesson Outcomes
Task 2:
Grade B
How I did
Met?
Partly met?
Not met?
Targets
How can I improve
on task 2?
How do we smell perfumes?
They evaporate and go into
our nose – there they
stimulate sense cells that
send messages to the brain.
How do they evaporate?
Perfumes are made of alcohols. Many alcohols evaporate
much quicker than water. The heat from our skin or from the
surrounding environment can make the alcohol evaporate,
taking the perfumes smell with it.
New Information for Task 3
Volatility: 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
Esters
Alcohol + acid  ester + water
alcohol
organic acid
ester made
smell of ester
pentanol
ethanoic acid
pentyl ethanoate pears
octanol
ethanoic acid
octyl ethanoate
pentanol
butanoic acid
pentyl butanoate strawberries
methanol
butanoic acid
methyl butanoate pineapples
bananas
Task 3: (Grade A/A*)
• Task 3:
1. Explain how we can smell
perfumes
2. What are esters?
3. What is needed to make an
ester?
4. How is ethyl methanoate
made?
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
Go back to your lesson outcome grid and fill out
the ‘How I did’ and the ‘Targets’ column.
Lesson Outcomes
Task 3:
Grade A/A*
How I did
Met?
Partly met?
Not met?
Targets
How can I improve
on task 3?
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 •
timer • access to pure ethanoic acid (corrosive), butanol (harmful) • 100 cm3
beaker containing 20 cm3 0.5M sodium carbonate solution (low hazard)