Carbonyls 1+2 Flashcards
(37 cards)
What reagents are used for the oxidation of primary alcohols?
Potassium dichromate + Sulfuric acid
What is used to reduce an aldehyde into a primary alcohol?
NaBH4
Tollens solution test- Observations and products
Silver mirror in presence of aldehydes
Ag1+—> Ag
Aldehyde—-> Ketone
Fehling’s solution test- Products and observations
Aldehyde- Ketone
Ca2+—-> Ca1+
Blue to red
Nucleophilic addition/ Reduction with NaBH4/ CN-
General equations (word)
Aldehyde+ NABH4 —> Primary alcohol
Ketone+ LiAlH4 (In dry ether)—> Secondary alcohol
Aldehyde/ Ketone + Cyanide + Acid —-> Hydroxy nitrile
Dangers of potassium cyanide
Irritant and dangerous when inhaled/ consumed
Can react with moisture to form hydrogen cyanide (toxic gas)
Carbonyl compound
A compound containing C=O group
Nucleophile
An electron pair donor
Addition reaction
A reaction in which two or more substances join together to produce one product
Optical isomerism
Occurs when a compound contains a chiral carbon atom, which leads to the formation of two different optical isomers called enantiomers
- Optical isomers are a pair of stereoisomers which are non-superimposable mirror images of each other and which rotate the plane of polarised light in opposite directions
Asymmetric carbon
Asymmetric carbon = chiral carbon atom, which means that the carbon is bonded to 4 different groups. This gives rise to optical isomers.
Chiral compound
A compound containing one or more chiral atoms
Optical isomers
A pair of stereoisomers which are non-superimposable images of each other and which rotate the plane of polarised light in opposite directions
Racemic mixture
A 50:50 mixture of two stereoisomers which, overall, has no rotary effect on the plane of polarised light because the rotation caused by each of the stereoisomers is cancelled out by the other
Plane polarised light
Waves which vibrate in one dimension only
Stereospecific
A process with a preference for one of the particular enantiomers.
Condensation
A reaction in which a small molecule (usually water) is released when two other substances join together
Hydrolysis
Breaking of bonds by the action of water
Biodiesel
A mixture of methyl esters and long-chain carboxylic acids
Properties of carboxylic acids
Weak acids
React with carbonates to form CO2
React with alcohols in the presence of strong acid catalyst to form esters
Uses of esters relating to properties
They have a sweet smell- useful for perfumes and food flavouring
They are polar- lots of organic compounds will dissolve in them- good for glues and solvents
Used as plasticisers- added during polymerisation
Esterification word equation
Carboxylic acid + Alcohol ——> (Strong acid catalyst) Ester + Water
Ester hydrolysis word equation (acid)
Ethyl ethanoate + H2O —–> (reflux with acid catalyst) Ethanoic acid + Ethanol
Ester hydrolysis word equation (base)
Ethyl ethanoate + Hydroxide ions —> (reflux) Ethanoate ions + Ethanol
