Organic chemistry

• Alkanes have the general formula CnH2n+2
• In organic chemistry, a functional group is a specific group of atoms that determines the chemical properties of a homologous series
• Homologous series are families of similar compounds with similar chemical properties due to the presence of the same functional groups
• Unsaturated compounds have at least one carbon-carbon double covalent bond
• General characteristics of homologous series:

  • Same functional group
  • Same general formula
  • Differing from one member by CH2 unit
  • Display a trend in physical properties
  • Share similar chemical properties
• Structural isomers are compounds with the same molecular formula but different structural formula
• Coal is a solid hydrocarbon fuel with properties like viscosity, which is its resistance to flow as a liquid, and volatility, which indicates how easily it evaporates
• Petroleum (crude oil) is a mixture of hydrocarbons that can be separated through distillation based on their different boiling points
• During fractional distillation, the hydrocarbons are separated by their different boiling points, with smaller molecules having lower boiling points and being more volatile
• The products of fractional distillation of crude oil include:

  • Refinery gas
  • Gasoline (petrol)
  • Naphtha
  • Kerosene/paraffin
  • Diesel oil
  • Lubricating oil
  • Fuel oil
  • Bitumen
• Substitution in chemistry involves replacing one atom or group of atoms with another atom or group of atoms
• Cracking is a process that breaks down long alkane chains into shorter alkene and alkane compounds or even hydrogen, typically carried out at temperatures between 500-700 °C
• Alkenes are involved in addition reactions like bromination, where a bromine molecule is added across the double bond to form a dibromo compound
• Hydrogenation is a reaction where hydrogen is added across a double bond, typically catalyzed by nickel at 200 °C
• Hydration, with steam, is a process that adds water across a double bond to form alcohols like ethanol, catalyzed by phosphoric acid at 300 °C and 60 atm.
• Acids have a pH less than 7, while bases have a pH greater than 7.
• A solution with a pH of 7 is neutral (neither acidic nor basic).
• Strong acids completely dissociate into H+ ions when they ionize, while weak acids only partially dissociate.
• The pH scale measures how acidic or basic a solution is on a logarithmic scale from 1 (very acidic) to 14 (very basic). Neutral solutions have a pH of 7.
• The pH scale measures how acidic or basic a substance is on a logarithmic scale from 1 to 14.
• Strong acids completely dissociate in water, releasing H+ ions.
• Weak acids only partially dissociate in water, releasing some H+ ions.
• Bases are substances that can accept protons (H+), forming negative ions called conjugate bases.
• The pH scale is used to measure the concentration of hydrogen ions (H+) in a solution.