Intermolecular forces of attraction (Edexcel GCSE Chemistry): Revision Notes
📚 Revision Notes
Intermolecular forces of attraction
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Intermolecular forces are the forces between molecules. These forces are generally weaker in smaller molecules and stronger in larger molecules. This means that larger molecules, like long hydrocarbons, tend to have stronger attractions between them than smaller molecules.
Ignition and Boiling Points
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Shorter Hydrocarbons (small molecules):
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Longer Hydrocarbons (large molecules):
Viscosity
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Viscosity is a measure of how easily a liquid flows.
Stronger intermolecular forces (as in larger hydrocarbons) make it harder for the liquid to flow, meaning these substances are more viscous. For example, syrup is more viscous than water because its molecules are larger and have stronger intermolecular forces.