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Formula types and bond counting

Formula types and bond counting

Comparison of ethanol as molecular formula C2H6O, structural formula CH3CH2OH, displayed formula with all bonds, and the -OH functional group highlighted

Organic chemistry at IGCSE is mainly about carbon compounds. Carbon usually forms 4 covalent bonds, hydrogen forms 1, and oxygen forms 2, so bond-counting helps you spot impossible displayed formulae.

Formulae, functional groups and terminology Lesson

  1. IGCSE
  2. /Chemistry
  3. /Formulae, functional groups and terminology

Step-by-step lessons covering CIE IGCSE Chemistry Formulae, functional groups and terminology for Core and Extended tier. Each lesson works through exam-style questions in Paper 1 and Paper 3 (Core) or Paper 2 and Paper 4 (Extended), plus Paper 5 or Paper 6 format. Build a solid grasp of atomic structure, bonding and the mole concept early, since these underpin almost every other topic, then move on to the more calculation-heavy quantitative and organic chemistry content.

Lessons