C1b

Question 1

How can perfumes be natural or artificial?

Answer 1

• esters are often used in perfumes
• esters are common in natural
• esters can be manufactured synthetically to use as perfumes or flavouring

Question 2

What is the process of esterification?

Answer 2

-carboxylic acid+alcohol–>ester+water
1-mix 10cm3 of both a carboxylic acid and alcohol
2-add 1cm3 of concentrated sulfuric acid as an acid catalyst
3-warm gently for 5 minutes
4-add 150cm3 of sodium carbonate solution to neutralise the acids
5-smell carefully by wafting the smell to your nose
-the fruity-smelling product is the ester

Question 3

What are the needed properties of perfumes?

Answer 3

• easily evaporates or it won’t reach any noses
• non-toxic: it mustn’t seep through your skin and poison you
• doesn’t react with water: or it could react to water in sweat
• doesn’t irritate skin: or you can’t apply directly to skin
• insoluble in water: if it was soluble in water is would wash off every time you got wet

Question 4

What are peoples opinions on testing cosmetic products on animal?

Answer 4

• worth testing on animals first to check it won’t damage humans
• it’s wrong to cause suffering to animals just to test the safety of cosmetics (especially when the results may be inconclusive)

Question 5

Why has testing cosmetics on animals been banned in the EU?

Answer 5

-because of concerns of animal welfare

Question 6

What are the properties of a solid?

Answer 6

• strong intermolecular forces of attraction
• particles don’t move
• definite shape and volume
• do not flow
• particles vibrate as they get hotter, causing them to expand slightly

Question 7

What are the properties of a liquid?

Answer 7

• some intermolecular forces of attraction
• particles are free to move but tend to stick together
• don’t keep a definite shape
• keep the same volume
• will flow to the bottom of a container
• particles constantly moving in random motion
• the hotter the faster they move

Question 8

What are the properties of a gas?

Answer 8

• no intermolecular forces of attraction
• free to move
• travel in straight lines and only interact when they collide
• no define shape or volume
• always fill any container
• particles move constantly with random motion
• hotter=faster

Question 9

How do we smell thing?

Answer 9

• liquid particles are heated they move faster
• some faster than others
• fast-moving particles at the surface will overcome the forces of attraction from the other particles and escape
• this is evaporation
• evaporated particles drift in the air
• smell receptors in our noses pick up the the chemical and we smell it

Question 10

What are the forces like in perfumes?

Answer 10

• the forces of attractions need to be very weak (volatile)
• you only need a little heat energy to evaporate perfume
• its easy for the particles to overcome this attraction and escape

Question 11

What is volatility?

Answer 11

-how easily a liquid evaporates