Chlorine, $$Cl_2$$   - pale green to colourless

Bromine, $$Br_2$$  - reddish brown change to colourless

Initiation, Propagation, Termination

UV light

Large alkane --> small alkane, alkene

Thermal

-> 800°C

Catalytic

-> 450°C

-> aluminium (III) oxide mixed with silica / zeolite

UV light

Hydrogen gas, $$H_2$$  

Thermal

-> 800°C

Nickel, Ni

140°C - 200°C

Halogen in $$CCl_4$$  

Room temperature

Chlorine, $$Cl_2$$   - pale green decolourised

Bromine, $$Br_2$$   - reddish brown decolourised

Bromine water

Room temperature

In the dark

Bromine, $$Br_2$$   - reddish brown decolourised

Hydrogen halides, HX (HCl, Hbr, HI)

Room temperature

Follows Markovnikov rule (Hydrogen atom added to carbon with greatest number of hydrogen atoms)

In the dark

steam in $$H_3PO_4$$  

300°C

Follows Markovnikov rule (Hydrogen atom added to carbon with greatest number of hydrogen atoms)

70atm

steam in $$H_3PO_4$$  

Dilute acidified potassium manganate (VII), $$KMnO_4$$  

Cold

Purple $$KMnO_4$$   decoulorised, brown precipitate ( $$MnO_2$$  ) formed

Can be used to identify structure of alkene 

Concentrated acidified potassium manganate (VII), $$KMnO_4$$  

Hot

Purple $$KMnO_4$$   decoulorised

Monomer

Concentrated acidified potassium manganate (VII), $$KMnO_4$$  

Hot

Purple $$KMnO_4$$   decoulorised

Halogen, X₂ (Cl₂, Br₂)

Presence of anhydrous FeX₃ or AlX₃ 

Room temperature

Purple $$KMnO_4$$   decoulorised

Concentrated HNO₃

Concentrated H₂SO₄

55°C

Yellow oil formed

halogenoalkene(RX)

Presence of anhydrous AlCl₃ or FeCl₃

Room temperature

In the dark

Steamy white fumes of HCl formed

acyl chloride (RCOCl)

Presence of anhydrous AlCl₃ or FeCl₃

Reflux on water bath

80°C

Steamy white fumes of HCl formed

Fuming H₂SO₄ (saturated H₂SO₄ with SO₃)

Heat under reflux

Concentrated H₂SO₄

80°C

Steamy white fumes of HCl formed

Benzene vapour, H₂(g)

Finely divided Nickel, Ni

High temperature

High pressure

Steamy white fumes of HCl formed

Halogens (Cl₂, Br₂) in CCl₄

Initiation, Propagation, Termination

Chlorine - pale green to colourless

UV light

Bromine - reddish brown to colourless

Acidified KMnO₄

Activating - electron donating (ortho-para), Deactivating - electron accepting (meta)

Heat under reflux

benzoic acid as product

alkyl group must have a benzylic hydrogen

Concentrated HNO₃

Activating - electron donating (ortho-para), Deactivating - electron accepting (meta)

Heat under reflux

30°C

alkyl group must have a benzylic hydrogen

Halogen, X₂ (Cl₂, Br₂)

Activating - electron donating (ortho-para), Deactivating - electron accepting (meta)

Presence of anhydrous FeX₃ or AlX₃

In the dark

Room temperature