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CHEM 101 Introduction to Fundamental Chemistry Spring Quarter 2008 SCCC. http://seattlecentral.edu/faculty/lcwest/ CHE 101. Total and net ionic equations: Ionic compounds when placed in water dissociate into ions. e.g.
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CHEM 101 Introduction to Fundamental Chemistry Spring Quarter 2008 SCCC http://seattlecentral.edu/faculty/lcwest/CHE101
Total and net ionic equations: Ionic compounds when placed in water dissociate into ions. e.g. NaCl(s) + H2O(l) Na+(aq) + Cl-(aq) + H2O(l) Acids and bases (which may or may not be ionic) also dissociate in aqueous solution. e.g. NaOH(s) + H2O(l) Na+(aq) + OH-(aq) + H2O(l) HCl(g) + H2O(l) H+(aq) + Cl-(aq) + H2O(l)
The extent to which water dissociates is so small we don’t separate it into ions when we write total and net ionic equations. H2O(l) H+(aq) + OH-(aq) Other covalent compounds are do not dissociate in water.
Determining the charge of an ion is done in two ways: • For a simple ion we use the periodic table • For polyatomic ions we must either • Know the charge • Deduce the charge by looking at the charge of the other ion • e.g. • NaOH → Na+ + OH- • Na2CO3 → 2Na+ + CO32- None of these methods have anything to do with oxidation number !!
Iron(III) sulfate has the formula Fe2(SO4)3 what is the charge of the sulfate anion ? -2
Oxidation number should not be confused with charge. They are related in a sense, but my advise is forget this connection and focus on the rules. The thing with oxidation numbers is practice makes perfect!
Know general formula’s for different types of reactions and whether they are redox or not. e.g. Combination reaction: A + B → C Decomposition reaction: C → A + B Single replacement reaction: A + BC → AB + C Double replacement reaction: AB + CD → AC + BD
The End !! Good Luck Thanks for being a great class !!