Esters Flashcards
What is biodiesel?
A fuel used in diesel engines that is not made from crude oil. It has good lubricating properties so helps reduce engine damage.
It is a mixture of the methyl esters of long-chain carboxylic acids. Usually made from vegetable oils.
Rape methyl ester (RME) is made from reacting rape seed oil with methanol. This renewable fuel is almost identical to the non-renewable diesal made from crude oil.
Acid anhydrides
Funtional group: -COOCO
They are fairly reactive organic compounds and are useful in organic synthesis.
React with alcohols to form an ester and a carboxylic acid.
Triglycerides:
where are they found?
what are they made of?
They are found in vegetable oils and animal fats.
They are the triesters of long-chain carboxylic acids and propane-1,2,3 triol (glycerol)
Each glycerol molecule is joined to three long carbon chain carboxylic acids, 3 of the same of 3 different.
Shorthand method of describing the structure of a fatty acid
First number shows no. of C atoms.
2nd no. shows no. of double bonds
In brackets location of double bonds are stated
How is margarine made?
Vegetable oils can be made into margarine by hydrogenation.
A nickel catalyst is used.
As hydrogen is added to the unsaturdted vegetable oil, the oils melting point increases so that it becomes a solid at room temp.
Also, the remaining C=C bonds are changed from cis to trans.
What is the problem with trans fats?
They have been linked to an increase in the levels of harmful cholesterol in the blood and that this in turn may cause coronary heart disease and stroke.
