AS level mechanisms Flashcards
Conditions for electrophilic addition of Alkenes with bromine
Br2 aqueous
Room temperature
Steps of electrophilic addition of alkenes with bromine
x4
1) Line from double bond to δ+ Br
2) Line from Br2 Bond to δ- Br
New diagram
3) Br bonded to one C. Other C = +. Br- lone pair with Line to the positive C
New Diagram
4) Complete dihalogenoalkane
Conditions for electrophilic addition of Alkenes with Sulphuric Acid
1) H2SO4 concentrated at room temperature
2) warm H2O
Steps of electrophilic addition of Alkenes with sulphuric acid (also applies for water)
(x4)
1) Line from double bond into δ+ Hydrogen
2) Line from OH bond to δ- Oxygen
New diagram
3) Lone pair HSO4 to the C+, other hydrogen now bonded to other C
New Diagram
4) HSO4 bonded into molecule
Conditions for electrophilic addition of Alkenes with hydrogen bromine (HBr)
HBr
HCl at room temperature
Steps for electrophilic addition of Alkenes with HBr
x4
1) Line from double bond to δ+ Hydrogen
2) Line from HBr Bond to Br
New Diagram
3) hydrogen bonded to molecule. Other carbon now positive. Line from lone pair Br- to C+
New Diagram
4) H and Br bonded into molecule with no charges
Conditions for Elimination of halogenoalkanes with ethanol can hydroxide ions
KOH
Ethanolic solution
Heated under reflux
Steps for elimination of halogenoalkanes with ethanolic solution
(x3)
1) Line from OH- lone pair to a hydrogen
2) Line from CH bond to CC bond
New Diagram
3) Alkene with Br- and H2O as other products
Conditions for acid catalysed elimination mechanism
Concentrated H2SO4 or H3PO4
Steps for acid catalysed elimination
1) Line from bonded Oxygen with a lone pair too the disassociated H+
New Diagram
2) Line from CO bond to the now positive Oxygen
New Diagram
3) Oxygen and attached hydrogens disappear. Line from CH bond to the CC bond. Other c is positive now
New Diagram
4) Alkene along with dissociated H+ shown
Conditions for Acid catalysed addition mechanism for hydration of ethene
1) Concentrated H2SO4
2) warm H2O
Steps for acid catalysed addition mechanism for hydration of ethene
1)Line from double bond to dissociated H+
New Diagram
2) line from lone pair in the Oxygen to the now positive carbon
New Diagram
3) Oxygen bonded to to the carbon. Oxygen now positive
4) Line from OH bond to O+
New Diagram
5) alcohol and H+
Conditions for nucleophilic substitution of halogenoalkanes with aqueous hydroxide ions
KOH aqueous
Heat under reflux
Steps for nucleophilic substitution of halogenoalkanes with aqueous hydroxide ions
1) Line from :OH- to δ+ Carbon
2) Line from CBr Bond to Br δ-
New Diagram
3) alcohol and :Br-
Conditions for nucleophilic substitution of halogenoalkanes with cyanide ions
Concentrated KCN in ethanol/ water mix
Heat under flux