Flashcards in What's in a medicine? Deck (41):
What is the name of this carboxylic acid? CH3CH(CH3)CH2COOH
Name this: (COOH)2
What do carboxylic acids form when they dissociate in aqueous solution?
oxonium ions, carboxylate ions
What do carboxylic acids form when they react with bases?
How do you form an ester?
What is the reaction called?
Reflux a carboxylic acid with an alcohol, using a strong acid catalyst
It is esterification reaction and is reversible
What derivatives are formed from carboxylic acids?
ester, acyl chloride, amide, acid anhydride
What is the test for phenols?
Neutral iron(iii) chloride solution forms a purple complex
What is the order of acidic strength fir alchols, phenols, carboxylic acids and water?
ethanol, water, phenol, ethanoic acid
Why are phenols and carboxylic acids more acidic?
More stable anion as the negative charge is delocalised across several atoms
What is the reaction of phenol and NaOH?
Forms salt C6H5O- Na+ and water
Reaction of ethanoic acid and Na2CO3?
Forms salt CH3COO-Na+, CO2 and water
Equation for limewater test?
CO2+Ca(OH)2 ----> CaCO3 (cloudy precipitate + water
How is ester hydrolysis carries out?
Acid hydrolysis- sulfuric acid catalyst
Alkaline hydrolysis- NaOH (forms carboxylate salt instead of acid)
Why is alkaline hydrolysis of esters preferred?
The reaction goes to completion
How do phenols form esters?
By reacting with acyl chlorides and rtp or acid anhydrides under reflux in anhydrous conditions for both.
How do you name an ester?
The first part is from the alcohol and the second is from the acid. The carbonyl group C=O is always from the acid.
Name this ester: HCOOCH2CH2CH3
What is the order of atom economy of reactions? (descending)
Rearrangement and addition, substitution and condensation, elimination.
Equation for % atom economy?
Mr of useful product/ Mr of reactants x 100
what functional group do both aldehydes and ketones contain?
carbonyl group C=O
What reactants are needed to make an aldehyde?
Primary alcohol and acidified potassium dichromate
Distill off aldehyde immediately to prevent further oxidation
What product do you get when a primary alcohol is heated under reflux with acidified potassium dichromate?
How do you make a ketone?
Reflux secondary alcohol with acidified potassium dichromate
what colour change happens in this reaction and does it happen with aldehydes or ketones?
Cr2O7 (2-) + 14H+ + 6e- ---> 2Cr3+ + 7H20
Dichromate ion is reduced, solution changes from orange to green in the presence of aldehydes (or primary and secondary alcohols)
What is Fehling's solution and what is it used for?
It is a solution of blue Cu2+ ions and alkali. It is used to distinguish between aldehydes and ketones, in aldehydes the Cu2+ is reduced to Cu+ turning from blue to an orange brown precipiatate. In ketones there is no colour change.
What is used to reduce aldehydes and ketones back to their alcohols?
NaBH4 sodium tetrahydridoborate
What reaction do aldehydes and ketones undergo in the presence of HCN and an alkali? What is the nucleophile?
Nucleophilic addition, CN-
what is the product of the reaction of an aldehyde or ketone with HCN ?
2-hudroxynitrile or cyanohydrin
What is the definition of an acid?
a proton donor
what is a base?
a proton acceptor
what is an alkali?
a base that dissolves in water to produce OH- ions
which is the acid and which is the base in this reaction?
HNO3 + H2O ---> NO3-+ H3O+
HNO3 is acid
H2O is base
what ions do acids become in aqueous solution?
oxonium ions H3O+
What is a conjugate acid?
A species which in the reverse reaction accepts protons
What does it mean if a species is amphoteric?
they can act as both an acid and a base
What are strong acids and how strong is their conjugate base?
Powerful proton donators and a weak conjugate base
what is the molecular ion?
Ion produced when the parent molecule has lost just one electron.
It is the peak with the greatest m/z on the spectrum.
What labels are on the axis of a mass spectrum?
x-axis is mass to charge ratio m/z
y-axis is intensity
what is the process by which the molecular ion breaks up?
what does the molecular ion tell you?
the molecular mass of the compound