Alkanes
Saturated: Contain no C double bond C or triple bond
General Formula: CnH2n+2
Boiling Points:
As chain length increases, BP increases, more VdWs between molecules
Higher branching = lower BP, less VdWs because molecules can’t get close together
Combustion:
Complete = CO2/H20/ clean flame, Incomplete= CO/H2O/sooty flame
Carbon burns with a yellow ish flame, hydrogen burns with a blue flame
Pollution from fossil fuels
C02 emissions have risen from 0.03 to 0.04%
Methods:
Remove sulphur from fuels before combustion
Using catalytic converters in cars
Scrubbing emissions from power stations and factories
Using renewable energy sources
Catalytic Converters
-Honeycomb ceramic structure, coated in metal catalyst
-metal coating keeps costs down, honeycomb structure = larger SA for reactions to take
place, can become poisoned by lead
Reduction 2NO→ N2 + 02
Reduction 2NO2 → N2 + 202
Oxidation CXHY + (x + y/4) 02 → XC02 + y/2 O2
Oxidation 2CO + 02 → 2C02
Reactions
Monohalogenation:
CH4 + CL2 → CH3Cl + HCl
CH3Cl + Cl2 → CH2Cl2 + HCl
CH2Cl2 + Cl2 → CHCl3 + HCl
CHCl3 + Cl2 → CCl4 + HCl
Saturated: Contain no C double bond C or triple bond
General Formula: CnH2n+2
Boiling Points:
As chain length increases, BP increases, more VdWs between molecules
Higher branching = lower BP, less VdWs because molecules can’t get close together
Combustion:
Complete = CO2/H20/ clean flame, Incomplete= CO/H2O/sooty flame
Carbon burns with a yellow ish flame, hydrogen burns with a blue flame
Pollution from fossil fuels
C02 emissions have risen from 0.03 to 0.04%
Methods:
Remove sulphur from fuels before combustion
Using catalytic converters in cars
Scrubbing emissions from power stations and factories
Using renewable energy sources
Catalytic Converters
-Honeycomb ceramic structure, coated in metal catalyst
-metal coating keeps costs down, honeycomb structure = larger SA for reactions to take
place, can become poisoned by lead
Reduction 2NO→ N2 + 02
Reduction 2NO2 → N2 + 202
Oxidation CXHY + (x + y/4) 02 → XC02 + y/2 O2
Oxidation 2CO + 02 → 2C02
Reactions
Monohalogenation:
CH4 + CL2 → CH3Cl + HCl
CH3Cl + Cl2 → CH2Cl2 + HCl
CH2Cl2 + Cl2 → CHCl3 + HCl
CHCl3 + Cl2 → CCl4 + HCl
