Organics Week 4 Flashcards
What is meant by dextrorotatory?
Dextrorotatory refers to the ability of an enantiomer to rotate plane-polarised light in a clockwise direction (+).
What is a racemate?
A racemate, also known as a racemic mixture, is a mixture that contains equal amounts of both enantiomers. It does not have the ability to rotate plane-polarised light.
What is optical isomerism?
Optical isomerism is a type of stereoisomerism in chemistry where compounds have the same structural formula but differ in the spatial arrangement of atoms, resulting in mirror-image isomers called enantiomers.
What are enantiomers?
Enantiomers are mirror-image isomers that cannot be superimposed on each other. They have the same structural formula but differ in their spatial arrangement of atoms.
What is a chiral carbon atom?
A chiral carbon atom is a carbon atom that is bonded to four different groups, resulting in a tetrahedral arrangement of these groups around the carbon.
What is laevorotatory?
Laevorotatory refers to the ability of an enantiomer to rotate plane-polarized light in an anticlockwise direction (-).
How do optical isomers differ in their properties?
They have similar physical and chemical properties but differ in their ability to rotate plane-polarised light.
What are the different types of isomerism?
There are different types of isomerism, including chain isomerism, position isomerism, and functional group isomerism.
What are the different effects of thalidomide depending on the enantiomer?
For example, thalidomide has different effects depending on the enantiomer, with one causing birth defects and the other having sedative properties.
What are optical isomers also known as?
Optical isomers, also known as enantiomers, are mirror images of each other and cannot be superimposed.
What is a racemic mixture?
A racemic mixture is formed when equal amounts of both enantiomers are present and it does not rotate plane-polarized light.
How can the stereochemistry of a molecule influence its drug action?
Different optical isomers can have distinct effects. For instance, one enantiomer of thalidomide causes birth defects, while the other has sedative properties.
How can chemical reactions lead to the formation of racemates?
Chemical reactions can lead to the formation of racemates, such as when unsymmetrical aldehydes and ketones react with HCN.
What does isomerism refer to in chemistry?
Isomerism in chemistry refers to the phenomenon where molecules with the same molecular formula have different structural arrangements.
What is the difference between structural isomers and functional group isomers?
Structural isomers have the same molecular formula but different structural arrangements, while functional group isomers share the same molecular formula but have atoms arranged to create different functional groups.
What is optical isomerism?
Optical isomerism is a type of stereoisomerism that involves the spatial arrangement of atoms.
What are functional group isomers?
Functional group isomers have the same molecular formula but different functional groups, such as aldehydes and ketones.
What is biodiesel?
Biodiesel is a fuel made from converting vegetable oils with methanol and a strong alkali catalyst. It consists of methyl esters of long-chain carboxylic acids.
What is delocalisation?
Delocalisation refers to the spread of electron density over multiple atoms or bonds in a molecule. In the case of carboxylic acids, delocalisation stabilises carboxylic acid salts, enhancing their dissociation.
What is hydrolysis?
Hydrolysis is a chemical reaction in which a compound reacts with water, resulting in the breaking of chemical bonds and the formation of new compounds. In the context of esters, hydrolysis can occur with either acid or sodium hydroxide.
What are the products obtained from the hydrolysis of fats and oils?
The hydrolysis of fats and oils produces soap, glycerol, and fatty acids.
What is the dual nature of fatty acids used in soaps and how does it help in cleaning?
Fatty acids have a hydrophilic end with a polar CO2- group that easily interacts with water and a hydrophobic end with a long non-polar hydrocarbon chain that attracts grease. This dual nature allows the emulsification of grease and water, making it easier to mix and remove them.
How are esters formed and what conditions are required for the reaction?
Esters are formed through esterification, a reversible reaction requiring prolonged heating under reflux with an acid catalyst.
How are carboxylic acid salts stabilised?
Carboxylic acid salts are stabilised by delocalisation, which enhances dissociation.
How are carboxylic acids named?
Carboxylic acids are named with the ending -oic acid and the carbon chain is numbered starting from the carboxylic acid end.
What are some of the uses of esters?
Esters have various uses such as solvents, plasticisers, and perfumes.
How can esters undergo hydrolysis and what are the differences between acid and sodium hydroxide hydrolysis?
Esters can undergo hydrolysis with either acid or sodium hydroxide, with the latter being a complete and irreversible reaction.
How would you use the properties of glycerol in a practical application?
Glycerol can be used in cosmetics, food products, and adhesive formulations due to its ability to readily form hydrogen bonds and its high solubility in water.
What are the properties of carboxylic acids in water?
Carboxylic acids are weak acids in water and can displace carbon dioxide from carbonates.
What is the process involved in the oxidation of alcohols using reflux?
The oxidation of alcohols using reflux involves a step-by-step process for practical setup and purification of organic liquid from esters produced by reflux.
How can hydrolysis of ethyl benzoate be achieved?
Hydrolysis of ethyl benzoate can be achieved by heating under reflux with sodium hydroxide, followed by cooling and addition of hydrochloric acid for filtration of benzoic acid precipitate.
