Fragrance part 1

Question 1

Define Odour threshold

Answer 1

The concentration in air that a gas, liquid, or solid can be detected by human senses.

Question 2

Define character impact compounds

Answer 2

compounds responsible for smell

Question 3

Need of smell?

Answer 3

volatility

Question 4

to vaporise easily compounds are generally?

Answer 4

non-polar (lipophilic) and have a small molecular weight

Question 5

Why are non-polar molecules more volatile?

Answer 5

They tend to have weak intermolecular forces holding them together.

Question 6

Difference between gas and vapour?

Answer 6

Gas’ are in gas form at room temperature, whereas vapour is something in a gas form but originates from a solid or liquid state.

Question 7

Define vapour pressure?

Answer 7

the pressure exerted from an vaporised materials from solid or liquid on the inside of a container.

Question 8

Higher volatility =

Answer 8

higher vapour pressure

Question 9

Define saturated vapour pressure

Answer 9

is the pressure exerted by a vapour in equilibrium with liquid of the same substance. It is influenced by temperature and pressure.

Or

the maximum pressure possible by water vapour at a given temperature

Question 10

Volatility of top notes?

Answer 10

Most volatile, smelt first and goes quickly. ie citrus

Question 11

Volatility of middle notes?

Answer 11

Evaporate slower than top notes. ie floral, jasmine, rose

Question 12

Volatility of base notes?

Answer 12

Slow to evaporate. ie woody, earthy, musty, amber

Question 13

Define fixatives?

Answer 13

Substances that interact with smell compounds and modulate the speed they evaporate.