Alkanes and Halogenoalkanes

• What are alkanes?

  saturated hydrocarbons
• What is the main source of alkanes?

  crude oil
• What happens to the boiling point as the chain length of alkanes increases?

  Increases
• What happens to viscosity as chain length of alkane increases?

  Increases
• What happens to flammability as chain length of alkane increases?

  Decreases
• What do alkanes react with?

  halogens under suitable conditions

  burn with oxygen
• What is the order of fractions in fractional distillation?

  Liquified Petroleum gas

  Petrol

  Kerosene

  Diesel

  Heavy fuel oil

  Bitumen
• What are the products of complete combustion?

  Carbon dioxide

  Water vapour
• What are the 3 possible products of incomplete combustion?

  Solid carbon

  carbon monoxide

  water vapour
• In the atmosphere what are carbon dioxide and water vapour?

  Greenhouse gases
• What is another term for the solid carbon produced by incomplete combustion?

  Soot
• What type of pollution does soot cause?

  smog
• Give 2 reasons why long chain hydrocarbons are cracked to smaller ones?

  Shorter chain lengths have more economic value as they are used in fuels

  Alkenes produced which are more reactive than alkanes
• What are alkenes used as?

  chemical feedstock
• Name 3 things alkenes are used to make?

  plastics

  paints

  drugs
• Why are alkanes unreactive and hard to break down?

  Alot of energy needed to break the strong carbon hydrogen and carbon carbon bonds
• What are the 2 types of cracking?

  Thermal and catalytic
• What are the conditions in thermal cracking?

  High temperature ( 700- 1200K)

  High pressure ( 7000 kPa
• What are free radicals?

  highly reactive molecules or atoms with unpaired electrons
• What does thermal cracking produce a high proportion of?

  alkenes
• What are the conditions for catalytic cracking?

  Temperature of 720K

  Lower pressure ( 100 kPa)

  Zeolite catalyst
• What structure do zeolites have?

  honeycomb structure
• What are the products produced from catalytic cracking?

  Branched alkanes

  Cycloalkanes

  Aromatic compounds
• What is the equation for the formation of nitrogen monoxide?

  N2 + O2 -> 2NO
• What do Nitrogen oxides react with to form nitric acid?

  water vapour and oxygen
• What does Sulfur dioxide combine with to form sulfuric acid?

  water vapour and oxygen
• Give the equation of fuel gas desulfurisation using Calcium oxide?

  CaO + 2 H2O + SO2 + 1/2 O2 → CaSO4.2H2O
• Give the equation of fuel gas desulfurisation using calcium carbonate?

  CaCO3 + SO2 + 1/2 O2 → CaSO4 + CO2
• Write an equation to show how NO is removed from exhaust gases in a catalytic converter? ( Reacting with carbon monoxide)

  2 NO + 2 CO → N2 + 2 CO2
• What are the products when NO react with unburnt hydrocarbons in catalytic converters?

  Nitrogen

  Carbon dioxide

  Water
• What 2 metals are used in catalytic converters?

  Palladium and rhodium
• Suggest why CaCO3 or CaO are used in flue gas desulfirisation?

  Neutralise acidic SO2 gas
• Are halogenoalkanes soluble in water?

  No
• What can halogenoalkanes mix with?

  hydrocarbons
• What can halogenoalkanes be used in?

  dry cleaning fluids

  remove oily stains
• What happens to the boiling point of halogenoalkanes as chain length increases?

  Increases
• What 2 factors determine how readily the C-X bond reacts?

  bond polarity

  bond enthalpy
• What is a nucleophile?

  electron pair donor with a lone pair of electrons on an electronegative atom that they can use to make a covalent bond
• What is bond enthalpy?

  energy needed to break a bond
• According to bond polarity which halogenoalkane should be most reactive?

  Fluoro compounds