Chapter 12, Problem 106A

Interpretation Introduction

Interpretation:

The diffusion rate as a property of perfume needs to be explained.

Concept introduction:

The diffusion model is based on Fick’s law. In the perfume, the fragrance solutions are non-ideal liquid mixtures. This diffusion model is applied to perfume mixture in concentrated form as well as a diluted form where the solvent is ethanol. This diffusion is due to the difference in concentration.

Explanation of Solution

When perfume is exposed to air in a room, the air as well as perfume particles get mixed and spread through the whole room from higher concentration to lower concentration. The diffusion rate of perfume is very high which depends on the ingredients. A basic ingredient in perfume is musk but they have high molecular weight thus, the rate of diffusion is less. The molecules with molecular weights less than 300 generally have high diffusion rates.

The other ingredients based on their functional groups are:

• Alcohols
• Esters
• Aldehyde
• Ketones
• Thiols
• Lactones

The high concentration of aldehydes may have overwhelming and pungent but when taken in low concentration can evoke a wide range of aroma.

The above chemical ingredients have low molecular weights thus, they diffuse at faster rates.