chapter 26 Flashcards
how do you make an aldehyde from a primary alcohol?
distillation
H+ /Cr2O7 2-
how do you make a ketone from a secondary alcohol?
reflux
H+ /Cr2O7 2-
what happens when you reflux a tertiary alcohol?
no reaction
what is the aldehyde functional group?
CHO
what is the ketone functional group?
CO
what happens when you oxidise aldehydes?
produces carboxylic acid
with H+ /Cr2O7 2-
why do carbonyls react with nucleophiles?
C=O bond is polar due to electronegativity difference
delta positive charge on carbon reacts with nucleophiles
aldehyde + 2[H]
alcohol
with NaBH4/H2O
ketone + 2[H]
alcohol
with NaBH4/H2O
what happens when carbonyls react with nucleophiles?
H- 2 electrons arrow to carbon atom
C=O bond to O atom
C=O has delta pos and neg charges
O- with two electrons arrow to H from water
H-O bond to O atom
produces alcohol + OH-
what happens to carbonyls when they are reacted with hydrogen cyanide (HCN)?
NC- triple bond arrow to carbon atom
C=O bond to oxygen atom
delta pos and neg charges on C=O
now single bond oxygen and extra carbon with triple bond to N
O- with two electrons arrow to H+
produces alcohol group
what happens when you add bradys’ reagent to aldehyde or ketone?
forms orange precipitate
dissolved in methanol and sulfuric acid
what happens when you add tollens’ reagent to aldehyde or ketone?
when added to aldehydes produces silver mirror
no reaction when added to ketones
Ag+ + e- –> Ag
what happens when compounds contain two carboxylic acid groups?
-dioic acid
what can carboxylic acids do with their O-H bond?
polar bond means it can hydrogen bond to themselves and water
as number of atoms in non-polar carbon chain increases, solubility increases
what are carboxylic acids are also classified as?
weak acids so partially dissociate when dissolved in water
what happens when carboxylic acids react with metals?
produces salt + H2
salt ends in -oate
redox reaction
what happens when carboxylic acids react with a base?
produces salt + water (neutralisation)
what are some examples of carboxylic acids reacting with a base?
ethanoic acid + CaO –> calcium ethanoate + water
methanoic acid + Na2CO3 –> sodium methanoate + CO2 + water
what are carboxylic acid derivatives?
compounds that can be hydrolysed to form the parent carboxylic acid
what are examples of carboxylic acid derivatives?
esters
acyl chloride
amide
acid anhydride
how do you name an acyl chloride?
named after parent carboxylic acid
e.g. ethanoyl chloride
how do you name an amide?
named after parent carboxylic acid
e.g. butanamide
what is a property of an acyl chloride?
very reactive so are easily converted back into carboxylic acids + derivatives
