Carboxylic Acids and Derivatives Flashcards
How many of the aliphatic carboxylic acids can dissolve in water and why can they?
The first 4 acids and this is because they can form hydrogen bonds to the water molecules.
What is the trend in strength of carboxylic acid as carbon chain increases and why?
The strength decreases as the longer the chain the more the electron density of the COO ion increases making it less stable.
What are the compounds used and formed in esterification?
Alcohol + Acid = ester + water
What are some common uses of esters?
They can be used in perfumes and flavourings
What are plasticisers?
They are compounds which can be used to allow the chains to move more easily and to make the polymer more flexible.
How can you split an ester up and what are the products?
Hydrolysis of esters can be obtained by either heating with an acid (reversible but does not have a good yield) or with NaOH (non reversible).
Both must be done under reflux
They must both be done with dilute acid/NaOH
glycerol and 3 carboxylate salts
What is the IUPAC name of glycerol?
propane 1,2,3 triol
What are some uses of glycerol and why is it good for those uses?
Glycerol is soluble in water and is used in cosmetics, food and glues
How do you make fats and oils from glycerol?
Add three long chain carboxylic acids
What are the products after the hydrolysis of vegetable oils and fats?
Glycerol, long chain carboxylic acids and soap
Why do long chain carboxylic acids act as soaps?
They have a polar head which mixes with the water and a hydrophobic tail with mixes with the grease and allows the water and grease mixture to wash away.
What are the conditions and reactants for converting oils to biodiesel?
oil + 3methanol = glycerol + biodiesel
When testing the melting point of a solid how can you tell whether it is impure or not?
The substance will start to melt before the suspected substances melting point and will melt over a range of temperatures.
What are the 6 steps in the purification of an organic solid (recrystallisation)?
Dissolve the impure solid in the minimum volume of hot ethanol
hot filter the solution through filter paper
Cool the filtered solution by using a beaker in cold ice water
use a Buckner funnel to separate out the crystals
rinse with distilled water
dry the crystals between absorbent filter paper
What are the products of an alcohol with an acid anhydride?
A carboxylic acid and an ester
