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Topic: BASES Do Now:. Topic: BASES Do Now:. IDENTIFY a Base Covalent Formulas metal + OH ( exception:NH 3 it’s a base too). Table L. CH 3 OH is NOT a base. WHY ?. Properties of Bases. Bitter taste Slippery or soapy feeling Electrolytes NaOH Na + ( aq ) + OH - ( aq )
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IDENTIFY a Base Covalent Formulas metal + OH (exception:NH3 it’s a base too) Table L CH3OH isNOTa base.WHY?
Properties ofBases • Bitter taste • Slippery or soapy feeling • Electrolytes • NaOH Na+(aq) + OH-(aq) • React with acids to produce water and salt • Bases turn litmusblue
Arrhenius Base • substance that contains hydroxide group & ionizes to produce OH-1 ions in aqueous solution NaOH(s) Na+1(aq) +OH-1(aq)
THERE IS A LIMITATION TO THIS MODEL… • NH3 is a base but it doesn’t contain OH-1 but it produces OH-1 :NH3 + H2O NH4+1 + OH-1
Bronsted-Lowry Base • Base = proton acceptor OH-1 is base • Not restricted to aqueous solution NH3 + H2O NH4+1 + OH-1 NH3 is a base!
Water is amphoteric! Amphoteric = Substance that acts as both acid & base
NamingBases • Name the metal + hydroxide NaOH = ? Ca(OH)2 = ? Mg(OH)2 = ? Sodium hydroxide Calcium hydroxide Magnesium hydroxide
Not all bases are created equal • Strong bases 100% dissociate • Group 1 and Group 2 metals + OH are considered Strong bases • NaOH Na+(aq)+ OH-(aq) • Weak bases • NH3
REVIEW • Acids: start with H or end with COOH • Produces H+ ions • Proton Donor • Bases: metal + OH • Produces OH- ions • Proton Acceptor