Smells

Question 1

what are cosmetics?

Answer 1

either synthetic or natural

Question 2

what are esters?

Answer 2

perfumes that can be made synthetically

Question 3

Recall the necessary physical properties of perfumes

Answer 3

• evaporates easily
• non-toxic
• does not react with water
• does not irritate the skin
• insoluble in water

Question 4

what does nail varnish remover do?

Answer 4

dissolves nail varnish colours

Question 5

define:
solvent
solute
solution
soluble
insoluble

Answer 5

• liquid in which the solute dissolves to make a solution
• the substance that dissolves in the solvent
• mixture of solvent and solute that does not separate out
• dissolves in water
• doesn’t dissolve in water

Question 6

where is testing of cosmetics on animals banned?

Answer 6

in the EU

Question 7

Explain why new cosmetic products need to be
thoroughly tested before they are permitted to be
used

Answer 7

to make sure that they don’t harm humans

Question 8

how are esters made?

Answer 8

Alcohol + acid -> ester + water

Question 9

Explain why a perfume needs certain properties:

Answer 9

• easily evaporates so that the perfume particles
can easily reach the nose
• non-toxic so it does not poison you
• does not react with water because otherwise the
perfume would react with perspiration
• does not irritate the skin otherwise the perfume
could not be put directly on the skin
• insoluble in water so it cannot be washed off
easily.

Question 10

Explain the volatility (ease of evaporation) of

perfumes in terms of kinetic theory:

Answer 10

• in order to evaporate particles need sufficient
energy to overcome the attraction to other
molecules in the liquid
• only weak attraction exists between particles in
the liquid perfume so it is easy to overcome this
attraction.

Question 11

Explain why water will not dissolve nail varnish

colours:

Answer 11

• attraction between water molecules is stronger
than attraction between water molecules and
particles in nail varnish
• attraction between particles in nail varnish is
stronger than attraction between water molecules
and particles in nail varnish.

Question 12

what can esters be used as?

Answer 12

solvents

Question 13

describe a solution

Answer 13

a mixture of solvent and solute that does not separate out

Question 14

Explain why people have different opinions about
whether the testing of cosmetics on animals is ever
justified

Answer 14

either it’s cruel to animals and there are better alternatives or it’s necessary to prevent humans being harmed