C1g - Smells

Question 1

Desirable physical properties of perfumes (5) + reasons

Answer 1

evaporates easily; so perfume particles can easily reach the nose

non-toxic; so it does not poison the user/make them ill

does not react w/ water; must not react with perspiration

does not irritate the skin; otherwise it could not be put directly on skin

insoluble in water; so it cannot be washed off easily

Question 2

Explain the volatility of perfumes in terms of kinetic theory (3)

Answer 2

to evaporate, particles need sufficient energy to overcome the attraction (IM forces) to other molecules in the liquid

only weak attraction (IM forces) exists between particles in the liquid perfume, less energy needed to overcome the
attraction (IM forces) and evaporate

thus volatility (ease of evaporation) is high

Question 3

How can you make an ester

Answer 3

alcohols react with acids to make an ester and water

Question 4

Describe how to carry out a simple experiment to make an ester(3)

Answer 4

mix 10cm3 of ethanoic acid with 10cm3 of ethano

add 1cm3 of conc sulfuric acid (catalyst) to the mixture

warm mixture to 60C

Question 5

What can esters be used as

Answer 5

solvents

Question 6

What is a solution

Answer 6

a mixture of solvent and dissolved solute that does not separate out

Question 7

Why won’t nail varnish dissolve in water? (3)

Answer 7

attraction (IM forces) 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

because the 2 substances are more attracted to themselves than e/o, they don’t form a solution

Question 8

Why is testing of cosmetics on animals banned in the EU? (2)

Answer 8

wrong to cause suffering to animals just to test the safety of a cosmetic, especially when the results of animal testing might not be conclusive
many cosmetic

alternatives to animal testing

Question 9

Animal testing pros (2)

Answer 9

helps researchers find new medicines to improve/maintain the health of humans/other animals

helps ensure new cosmetics/medicines are safe to use and won’t damage humans

Question 10

Animal testing cons (2)

Answer 10

expensive to look after animals

wrong to cause suffering to animals just to test the safety of a cosmetic, especially when the results of animal testing might not be conclusive
many cosmetic