UNIT 2 NATURES’ CHEMISTRY HC CHEMISTRY UNIT 2 HC CHEMISTRY NATURES’ CHEMISTRY Esters, fats and oils Soaps, detergents and emulsions Proteins The chemistry of cooking and oxidation Fragrances Skin care COPY

NATURES’ CHEMISTRY Organic chemistry is the study of carbon compounds. This unit offers us a glimpse of the chemistry of carbon compounds we encounter in the food and drink we consume, the soaps we use to clean, and the products we use to protect our skin. You will learn to appreciate the chemistry behind familiar products and learn how the principles of bonding can help us understand the properties and uses of the compounds we find in everyday life.

Previous knowledge from National 5 Chemistry NATURES’ CHEMISTRY Previous knowledge from National 5 Chemistry That molecular structure and physical properties of hydrocarbons are related. The names, molecular and structural formula of alkanes (C1-C8), alkenes (C2-C8) and cycloalkanes (C3-C8) straight and branched. How to identify isomers and draw their structural formulae. What is meant by saturated and unsaturated carbon compounds and how they can be distinguished. Addition reactions Alcohol functional group –OH and properties of alcohols The names, molecular and structural formula of alcohols (C1-C8), straight and branched. Carboxylic acids functional group COOH and properties of carboxylic acids The names, molecular and structural formula of carboxylic acids (C1-C8), straight.

Organic Chemistry Originally, chemical compounds were divided into 2 classes: Inorganic or Organic Organic compounds were derived from living things. It was believed that they contained a ‘vital force’ and could not be made from inorganic compounds (non-living sources). Organic chemistry is the study of carbon compounds

Organic Chemistry Organic chemistry is basically the study of compounds containing carbon (with the exclusion of oxides and carbonates). There are so many compounds containing carbon that a whole branch of chemistry is devoted to their study. Organic molecules may be as simple as methane, CH4 HO or as complicated as cholesterol

(A) ESTERS, FATS AND OILS HC CHEMISTRY HC CHEMISTRY NATURES’ CHEMISTRY (A) ESTERS, FATS AND OILS

(A) ESTERS, FATS AND OILS HC CHEMISTRY HC CHEMISTRY (A) ESTERS, FATS AND OILS ESTERS

(A) ESTERS, FATS AND OILS NAMING AND DRAWING ESTERS HC CHEMISTRY HC CHEMISTRY (A) ESTERS, FATS AND OILS NAMING AND DRAWING ESTERS After completing this lesson you should be able to : At higher, structural formula may be shortened or full. Name an ester given the names of the parent carboxylic acid and alcohol or from structural formulae. Draw structural formulae for esters when given the names of the parent alcohol and carboxylic acid or the names of esters. Understand that esters are formed by the condensation reaction between carboxylic acid and an alcohol. The ester link formed is between the hydroxyl group and the carboxyl group. In condensation reactions, the molecules join together with the elimination of a small stable molecule, in this case water.

COPY Esters Esters are formed between an alkanol (alcohol) and alkanoic acid (carboxylic acid). Very slow reaction, unless an acid catalyst is used (usually sulfuric acid) During this reaction water is formed so it is called a condensation reaction. The term often used for the formation of esters is esterification . Esterification is a reversible reaction discussed later. H+ Alcohol + Carboxylic Acid Ester + Water

COPY Naming Esters An ester can be named given the name of the parent alcohol and carboxylic acid or from shortened and full structural formulae. The parent alkanol gives the start of the name ending in -yl. The parent acid gives the second part of the name ending in -oate. So the ester formed by reacting ethanol with propanoic acid would be ethyl propanoate…

An ester can be identified by the name endings ‘-yl –oate’. COPY An ester can be identified by the name endings ‘-yl –oate’. Esters contain the carboxylate functional group (–COO–)… Carboxylate group (ester link)

Naming esters. A B C D Which box shows ethylmethanoate? propylethanoate? methylethanoate? Box C Box B Box A methanol propanoic methylpropanoate The ester in box D is made from ………………………… and …………………………………. acid and is called …………………………………………………

Name of carboxylic acid Full structural formula of ester COPY Name of alcohol Name of carboxylic acid Name of ester Full structural formula of ester Ethanol Propanoic acid Ethyl propanoate   Propanol Methanoic acid Propyl methanoate  Methanol Butanoic acid  Methyl butanoate Ethanoic acid  Propyl ethanoate  Butanol Methanoic acid  Butyl methanoate  Ethanol Butanoic acid  Ethyl butanoate