solubility,+precipitation+reactions,+pH


 * //Maintaining water quality// **


 * Videos**

Factors affecting solubility with questions || media type="custom" key="23860392" Reading solubility curves (solubility of ionic compounds and gases) || media type="custom" key="23860460" Concentration of solutions ||
 * media type="custom" key="23860320"

Precipitation reactions || media type="custom" key="23861546" Acids and bases || media type="custom" key="23862122" The pH scale ||
 * media type="custom" key="23860566"


 * Common misconceptions:**
 * Strength (of acids and bases) and concentration mean the same thing.
 * Mass decreases on dissolving.
 * Substances containing H are acidic; substances containing OH are basic.
 * A concentrated acid is a pure substance.
 * The total mass increases in a precipitation reaction because the precipitate produced is solid and it is heavier than a liquid.


 * Interesting facts:**
 * A mixture of concentrated hydrochloric acid and nitric acid (called 'aqua regia') is strong enough to dissolve otherwise unreactive gold.
 * Concentration is the number of moles of solute that are dissolved in one liter of solvent. Strength is the percentage of those molecules that dissociate into ions.
 * Some weak acids (e.g. acetic) actually increase in strength as their concentration decreases.
 * It was once thought that acids tasted sour because their molecules were 'spiky' and bases were slippery because their molecules were round.
 * Alcohols have a characteristic hydroxyl group, OH, covalently bonded to the rest of the molecule. When alcohols dissolve in water they also dissolve molecularly and do not ionize. Since no OH- ions are released, alcohols are not bases.


 * Resources:**
 * Chemistry resource for students and teachers from Oklahoma State University.
 * [|Chemical reactions and chemical misconceptions] from the Royal Society of Chemistry.
 * Precipitation from the Royal Society of Chemistry.