Organic Chem Flashcards
Alkane -> halogenoalkane
Cl2/ Br2 in UV light/heat
Substitution
Why are alkanes generally unreactive?
- they contain relatively strong C-C and C-H bonds
- they are non-polar: they do not contain any region of high electron density - do not attract any electrophilic reagents + they do not contain any electron-deficient site to attract any nucleophilic reagents
Excess Cl2 in UV light reaction
Basically more H gets substituted
Combustion of hydrocarbon/alkane
Forms CO2 and H2O
Cis trans isomerism explanation
- restricted rotation due to C=C bond
- 2 different atoms/groups of atoms attached to each doubly bonded C atom
Cis trans melting point
Cis melting point lower than trans melting point:
The cis molecules pack poorly in the solid lattice as the two bulky groups are located on the same side in the molecule -> larger distances between molecules -> weaker intermolecular forces -> lower melting point
Alkene —> dihalogenoalkane (alkane with 2 halogens)
X2 in CCl4, room temperature in the dark
Addition
Observation: rapid decolourisation of orange-red Br2
Alkene to alkane
Reduction
H2 in Ni Catalyst, heat
Halogenoalkane —> alcohol
NaOH(aq) / KOH(aq) , heat
Substitution
Halogenoalkane —> alkene
Elimination
Ethanolic KOH/NaOH, heat
Other products: H2O + X-
alcohol -> alkene
Elimination
Excess conc H2SO4 / Al2O3
Heat
Oxidation of alcohols
K2Cr2O7 + H2SO4 / KMnO4 +H2SO4
Heat
Orange solution turns green / purple solution decolourises
Oxidation of alcohols
K2Cr2O7 + H2SO4 / KMnO4 +H2SO4
Heat
Orange solution turns green / purple solution decolourises
Forming esters with carboxylic acid and alcohol
Carboxylic acid + alcohol —> ester + H2O
Conc H2SO4 (as catalyst) , Heat
Condensation
Forming amide
Carboxylic acid + amine ( only secondary and primary amine can) , DCC, heat
Condensation
Acidic hydrolysis
Ester + H2O -> Carboxylic acid + HO-R
H2SO4(aq) / HCl (aq)
Heat
Hydrolysis
Basic hydrolysis
Ester + OH- -> Carboxylic acid but without the H+ LOL + HO-R
NaOH/KOH
Heat
