12.3, 12.4 Alkanes, Alkenes

Alkanes
> __ (only C-C); starts w/ C__
> generally __ (each C has __ c__ bonds = __ valencey)

saturated, CH4, unreactive, 4 covalent, full

Alkane reactions
1. __ combustion (p__ O₂ supply)
> Alkane + __ → __ + H__

complete, plentiful, o2, co2, h2o

Alkane reactions
2. __ combustion (l__ O₂ supply)
> Alkane + __ → __ + H__

incomplete, limited, o2, co, h2o

Substitution reactions in __ (alkanes/alkenes)
> 1 group r__ another; undergoes in presence of __ light
e.g. alk. + chlorine → c__ + hydrogen chloride
> CH₄ + Cl₂ —(__ light)→ CH₃Cl + HCl

alkanes, replaces, UV, chloroalkane, UV

Alkenes
> __ (≥1 C=C); starts w/ C__

unsaturated, c2h4

Naming alkenes
> alkenes ≥butene can have __ in diff places
> start from end w/ __ amt of C bonds (eg CH₂ instead of CH₃)

C=C, lowest

Cracking

breaking up larger hc into smaller useful ones via heating & catalyst

Why crack?
> matches s__ of f__ w/ d__
> makes u__ al__ e.g. feedstock

supply, fractions, demand, useful alkenes

Addition reactions will have C_C → C_C

=, -

Addition of H₂ (h__)
e.g. et__ + h__ → et__; w/ n__ catalyst

hydrogenation, ethene, hydrogen, ethane, nickel

Addition of Br₂ (h__)
> et__ + b__ → _,_-d__

halogenation, ethene, bromine, 1,2-dibromoethane

Colours
> ethene: __
> bromine: __
> 1,2-dibromoethane: __

colourless, brown, colourless

Addition of H₂O (h__)
> al__ reacts w/ s__ → a__; w/ p__ a__ c__

hydration, alkene, steam, alcohol, phosphoric acid catalyst

Tests for alkane/alkene
> w/ __(aq)
>> al__: no c__ (brown)
>> al__: brown → c__

br2, alkane, change, alkene, colourless