Alkanes

• What type of hydrocarbons are alkanes and what does this mean?

  Saturated hydrocarbons, contain single carbon-carbon bonds only
• What is the general formula for alkanes?

  CnH2n+2
• How do alkanes differ from each other?

  They differ by a CH2
• How many single bonds does every carbon in an alkane have?

  Four single bonds
• What are cycloalkanes?

  Saturated alkanes in a ring structure
• How does boiling point change with increasing chain length in alkanes?

  Boiling point increases due to more van der Waals forces
• What is petroleum primarily composed of?

  A mixture of hydrocarbons, mostly alkanes
• What happens to hydrocarbons as they rise in the fractioning column?

  They condense at different points
• How is crude oil separated into useful fractions?

  By fractional distillation
• What is the residue in fractional distillation?

  The largest hydrocarbons that don't vaporize
• What is the purpose of cracking in hydrocarbons?

  Conversion of long hydrocarbons into shorter chains by breakage of C-C bonds
• What are the two types of cracking?

  Thermal cracking and catalytic cracking
• What is the temperature for thermal cracking?

  High up to 1000°C
• What is the pressure for catalytic cracking?

  Slight - 1-2 atmospheres
• What catalyst is used in catalytic cracking?

  Zeolites
• What is the benefit of using zeolite in catalytic cracking?

  It lowers costs by reducing pressure and temperature
• What is the equation for complete combustion of alkanes?

  Alkane + oxygen → carbon dioxide + water
• What is produced during incomplete combustion of alkanes?

  Carbon monoxide and water
• What pollutants are produced from burning fossil fuels?

  Carbon dioxide, carbon monoxide, soot, unburned hydrocarbons, sulfur dioxide, nitrogen oxides
• How is carbon dioxide formed during combustion?

  From complete combustion of fuels containing carbon
• What problem does carbon dioxide cause?

  Global warming due to greenhouse gas effect
• How can the problem of carbon dioxide be reduced?

  By reducing fossil fuel consumption
• How is carbon monoxide formed?

  From incomplete combustion of fuels containing carbon
• What problem does carbon monoxide cause?

  It is poisonous and toxic
• How can carbon monoxide be reduced?

  By ensuring a good supply of oxygen
• How are carbon particulates formed?

  From incomplete combustion of fuels containing carbon
• What problems do carbon particulates cause?

  Breathing problems and global dimming
• How can carbon particulates be reduced?

  By ensuring a good supply of oxygen
• How are unburned hydrocarbons formed?

  Some fuel may not actually burn
• What problem do unburned hydrocarbons cause?

  They waste fuel and react with NO2
• How can unburned hydrocarbons be reduced?

  By ensuring engines are well-tuned
• How is sulfur dioxide formed?

  From burning fossil fuels containing sulfur impurities
• What problem does sulfur dioxide cause?

  It leads to acid rain formation
• How can sulfur dioxide be removed?

  By flue gas desulfurisation
• How are nitrogen oxides formed?

  From reactions between nitrogen and oxygen at high temperatures + high pressure
• What problem do nitrogen oxides cause?

  They contribute to acid rain and smog
• How can nitrogen oxides be reduced?

  By using catalytic converters
• What is the function of catalytic converters?

  To reduce levels of polluting gases
• What materials are catalytic converters made of?

  Ceramic material coated with platinum and rhodium
• What gases are considered greenhouse gases?

  CO2, CH4, and water vapor