Beginner Topic 294 of 1102 States of Matter & Solutions
Like Dissolves Like
Polar solutes dissolve in polar solvents and nonpolar solutes in nonpolar solvents.
Practise States of Matter & Solutions All States of Matter & Solutions topics
In-depth explanation of Like Dissolves Like
The principle like dissolves like states that substances with similar intermolecular forces tend to mix well with one another. Polar and ionic solutes dissolve readily in polar solvents such as water, while nonpolar solutes dissolve in nonpolar solvents such as hexane. The principle works because a strong interaction between solute and solvent can compensate for the energy needed to separate the molecules of each. Oil and water do not mix because breaking the hydrogen bonds between water molecules costs more energy than the weak dispersion forces formed with oil. Predicting solubility from molecular polarity is a central idea in chemistry.
Going deeper: Like Dissolves Like
Key ideas: Use polarity and hydrogen bonding to predict: ionic and polar solutes in polar solvents, nonpolar in nonpolar. Ethanol mixes with water through hydrogen bonding, while long-chain alcohols become less soluble as the nonpolar chain grows. Vitamins are classified as fat-soluble (A, D, E, K) or water-soluble (B, C).
Common mistakes and connections: Common errors are assuming that anything with an OH group dissolves in water regardless of size, or that large organic molecules with a few polar groups are polar. Another is thinking like dissolves like is a strict rule; it is a heuristic with exceptions. Links to intermolecular forces, polarity, solvation and chromatography.
Visualization of Like Dissolves Like
Like dissolves like: polar water dissolves ionic and polar solutes through dipole attraction, while nonpolar oils dissolve in nonpolar solvents. The interactive lesson shows this as a live animation or chart.
Worked example and use case
Iodine dissolves well in hexane, a nonpolar solvent, but it barely dissolves in water.
Frequently asked questions about Like Dissolves Like
What is Like Dissolves Like?
Polar solutes dissolve in polar solvents and nonpolar solutes in nonpolar solvents.
Is Like Dissolves Like a beginner, intermediate or advanced topic?
Like Dissolves Like is a beginner topic in States of Matter & Solutions. It needs no earlier chemistry lessons and is a good starting point.
What should I learn before Like Dissolves Like?
Study these earlier topics in States of Matter & Solutions first: Solute and Solvent, Solubility, Saturated Unsaturated Supersaturated.
What comes after Like Dissolves Like?
The next topics in States of Matter & Solutions are Molarity and Molality.
Can I practise Like Dissolves Like with quizzes?
Yes. The interactive lesson includes a self-check question on Like Dissolves Like, and the States of Matter & Solutions quiz draws on every topic in this area.
Where Like Dissolves Like fits in States of Matter & Solutions
Like Dissolves Like is topic 75 of 109 in States of Matter & Solutions.