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Cosmetics play an important part
in the life of teenagers and this unit considers some cosmetic products:
perfumes and nail varnish remover.
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Be able to understand the properties of these products and
appreciate the
need for testing new cosmetic products are considered.
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Appreciate the ethical issues
involved on the testing of cosmetics on
animals eg “Is testing of cosmetics on animals ever justified?".
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Practical and research
investigations you did may include:
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a) nail varnish removal,
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b) the preparation
of an ester eg butyl ethanoate,
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c) microscale preparation of a range of esters and identification of the smells,
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d) the removal of coloured nail varnish
with different solvents
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Understand that cosmetics are either synthetic
or natural depending on their source.
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Know that esters are perfumes that can be
made synthetically.
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Know about the
properties and uses of perfumes.
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Know the necessary physical properties of perfumes:
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Know and understand that nail-varnish remover dissolves nail
varnish colours.
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Know and understand the terms:
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a) solvent
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b) solute
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c) solution
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d) soluble
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e) insoluble.
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Know
that testing of cosmetics on animals is banned in the EU.
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Be able to explain why new
cosmetic products need to be thoroughly tested before they are permitted to be
used.
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Know that alcohols react with acids to make an ester and
water.
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Be able to describe how to carry out a simple experiment to make an ester.
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Be able to explain why a perfume
needs certain properties:
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easily evaporates so that the perfume particles
can reach the nose,
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non-toxic so it does not poison you,
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does not react with
water because otherwise the perfume would react with perspiration,
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does not irritate the skin otherwise the perfume
could not be put directly on the skin,
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insoluble in water so it cannot be
washed off easily.
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HT only: Be able to
explain the volatility (ease of evaporation) of perfumes in terms of kinetic
theory:
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a) in order to evaporate
particles need sufficient energy to overcome the attraction to other
molecules in the liquid
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b) only weak attraction exists
between particles in the liquid perfume so it is easy to overcome this
attraction
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Know that esters can be used as solvents.
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Be able to describe a
solution as a mixture of solvent and solute that does not separate out.
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Be able to interpret information on the effectiveness of solvents (no recall expected).
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HT only: Be able to explain why water will not dissolve nail varnish colours:
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a) attraction between
water molecules is stronger than attraction between water molecules and
particles in nail varnish,
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b) attraction between particles in nail varnish is
stronger than attraction between water molecules and particles in nail varnish.
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HT only: Be able to explain why testing of cosmetics on animals has been banned in the EU.
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Be able to explain
why people have different opinions about whether the testing of cosmetics on
animals is ever justified.
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Notes:
