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Example Answers (on handout). Soluble or Insoluble? K 3 PO 4 Soluble Fe 3 (PO 4 ) 2 Insoluble PbCl 2 Insoluble (exception) FeSO 4 Soluble (NH 4 ) 2 S Soluble (exception) PbS Insoluble. Announcements. LAB THIS WEEK- ANALYSIS OF SILVER GROUP IONS
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Example Answers (on handout) Soluble or Insoluble? • K3PO4 Soluble • Fe3(PO4)2 Insoluble • PbCl2 Insoluble (exception) • FeSO4 Soluble • (NH4)2S Soluble (exception) • PbS Insoluble
Announcements LAB THIS WEEK- ANALYSIS OF SILVER GROUP IONS OWL HOMEWORK- NEW ASSIGNMENTS POSTED ACID-BASE, SOLUBILITY, NET IONIC EQUATIONS
Which of the following is soluble? 0 Seconds Remaining • AlPO4 • PbBr2 • Al(OH)3 • FeSO4
Which of the following is insoluble? 0 Seconds Remaining • Al(NO3)3 • PbC2O4 • NaOH • FeF3
pH Review • What is the pH of a 0.25M solution of NaOH? • pH + pOH = 14 pOH=-log[OH-] • NaOH is a strong base [NaOH]=[OH-] pOH= -log[0.25]=0.602 pH= 14 - pOH = 14 = 0.602 = 13.4 • What is the [H3O+] of this solution? • [H3O+] = 10-pH = log-1(-pH) [H3O+] = 10(-13.4) = 3.98 x 10-14M
Conjugate Acid-Base Pairs • Anions of weak acids are weak bases • Conjugate acids and conjugate bases • Example: CH3COOH = weak acid CH3COO- = weak base What would this look like in a reaction? CH3COONa + HCl ? • Anions of strong acids are neutral
Conjugate Acids and Bases- More Examples • HCl + NaCN ? • HNO3 + AlPO4 ?
Net Ionic Equations • Write all reactants as they exist in solution • Identify acids and bases • Need both acid and base present • Look for “hidden bases” (anions of weak acids) • Ions that form insoluble compounds will form precipitates • Look for known gas-forming reactions • Write out the products as they exist in solution • Cancel spectator ions
Precipitation ReactionsNet Ionic Equations Pb(NO3)2 + K2CrO4 ? Pb(NO3)2 + KI ? Ba(NO3)2 + Na2C2O4 ?
Gas Forming Reactions • Special class of acid-base reactions • Combination of double displacement (swap) and decomposition reactions • 2HCl + Na2CO3 ?