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17-2: Precipitates. Ion product (Q). Can be compared with Ksp to determine if an aqueous soln of ions is supersaturated and will form a precipitate Ksp< Q, soln is supersat., will ppt Ksp > Q, soln is unsat, will accept more ions Ksp = Q, soln is saturated. Precipitation rxn.
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Ion product (Q) • Can be compared with Ksp to determine if an aqueous soln of ions is supersaturated and will form a precipitate • Ksp< Q, soln is supersat., will ppt • Ksp > Q, soln is unsat, will accept more ions • Ksp = Q, soln is saturated
Precipitation rxn • A rxn in which 2 solns are mixed and a ppt forms • Use solubility rules on page 574 to predict if a ppt will form, and it so, what it is • All are double replacement reactions
Driving Forces of Rxns • Driving forces allow less energy and are more stable • formation of a ppt • formation of a gas • formation of water
Complete ionic equation • shows all soluble ionic substances as ions • Ex:
Net ionic equation • Includes only those ions that undergo a change • Ex:
Spectator ions • ions that do not take part in a rxn • appear both before and after a reaction