CLASS 8 · LEARNING KNOWLEDGE

Water and intermolecular forces – basic principles

How it works

Water is a molecule made up of two hydrogen atoms and one oxygen atom (H2O). It is a polar molecule because the electrons are distributed unevenly. Various intermolecular forces act between the molecules: hydrogen bonds (between H and O in neighboring water molecules), dipole-dipole forces (between polar molecules) and van der Waals forces (between all molecules, especially nonpolar ones). These forces influence the properties of water, such as the high boiling point, surface tension and solubility.

Note
Intermolecular forces arise from attraction between molecules, with hydrogen bonds being particularly strong and occurring in molecules with H bonded to F, O or N.

An example

Which type of bond holds the individual water molecules together in liquid water?

Hydrogen bonds act between the water molecules. These arise because the hydrogen atom of one molecule is attracted to the oxygen atom of another molecule. This is stronger than purely dipole-dipole forces.

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50 Exercises · three difficulty levels · selection and number input

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Own explanation and own practice exercises by AmyMath. Subject reference framework: KMK Educational Standards Mathematics ESA/MSA. The topic assignment may vary by federal state.