the+dissociation+of+soluble+ionic+solutes;+the+ionisation+of+polar+molecules+such+as+acids;+the+separation+of+non-ionising+polar+molecules+such+as+ethanol


 * //Ways in substances behave in water// **


 * Videos**

The dissociation of NaCl || media type="custom" key="23675162" The polarity and solubility of biologically important molecules || media type="custom" key="23675178" The ionisation of different acids ||
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Space between molecules, methanol + water ||
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 * Common Misconceptions**
 * Dissolving doesn't occur in cold water.
 * The volume of a mixture of alcohol and water decreases in volume because the alcohol evaporates off.
 * Covalent molecular compounds are more polar than ionic compounds.
 * Ethanol dissociates into ions when it is dissolved in water

> dissolve in warm water since the particles disperse more readily.
 * Interesting Facts:**
 * Smaller crystals of ionic compounds dissolve more rapidly than larger crystals because of their larger surface area exposed to the water.
 * Dissolving does occur in cold water. E.g. salt dissolves quite readily in cold water since the particles in the liquid are still moving. Slightly more salt will
 * All nitrates, ammonium compounds and compounds of group 1 metals are soluble.
 * A solution is a homogeneous mixture in which molecules or ions are evenly dispersed throughout a solvent.
 * When ethanol dissolves in water, hydrogen bonds between water molecules and ethanol molecules are formed - but ethanol does not dissociate.
 * The order of increase in bond polarity: Non-polar covalent molecular compounds < Polar covalent molecular compounds < Ionic compounds.


 * Resources:**
 * Salts and solubility from PhET.
 * Water as a solvent tutorial from Sophia.
 * Mixing alcohol with water lab from David W. Brooks.