CHAPTER 6 STUDY GUIDE JULY 7 2010 AQUEOUS SOLUTIONS ELECTROLYTES AND EXTENT OF IONIZATION aqueous solutions consist of a solute dissolved in water classification of solutes 1 non electrolytes solutes that do not conduct electricity in water because they do not form ions when dissolved in solution ions conduct electricity in solution ionize slightly in water typically 1 5 examples of non electrolytes include C2H5OH ethanol contains only non metals contains no metals or polyatomic ions cannot produce ions in water C6H12O6 glucose blood sugar contains only non metals cannot produce ions in water C12H22O11 sucrose table sugar contains only non metals cannot produce ions in water 2 strong electrolytes solutes that ionize essentially 100 in water examples of strong electrolytes include strong soluble acids such as HCl HNO3 etc strong soluble bases such as NaOH KOH etc soluble ionic compounds such as NaCl KBr etc 3 weak electrolytes solutes that conduct electricity extremely well in dilute aqueous solutions because they form ions when dissolved in solution ions conduct electricity in solutions conduct electricity poorly in dilute aqueous solutions because they form very few ions when dissolved in solution ions conduct electricity in solutions examples of weak electrolytes include CH3COOH acetic acid vinegar COOH 2 oxalic acid weak bases such as NH3 Fe OH 3 etc some soluble covalent salts which ionize in water much less than 100 the electrolyte chart strong electrolytes strong bases strong acids water soluble salts ELECTROLYTES weak electrolytes weak acids weak bases non electrolytes covalent compounds non metals insoluble salts AQUEOUS SOLUTIONS STRONG AND WEAK ACIDS acids substances that generate hydrogen ions H or H3O in aqueous solutions strong acids ionize 100 in water only ions are produced common strong acids and their anions know this list all others are weak acids STRONG ACIDS formula ANIONS formula name name 1 weak acids ionize significantly less than 100 in water typically ionize about 1 5 common weak acids and their anions do not need to memorize these for the test ANIONS formula name fluoride ion acetate ion HCl HBr HI HNO3 HClO4 HClO3 H2SO4 CHAPTER 6 STUDY GUIDE JULY 7 2010 hydrochloric acid Cl hydrobromic acid Br hydroiodic acid nitric acid perchloric acid chloric acid sulfuric acid I NO3 ClO4 ClO3 HSO4 SO4 2 WEAK ACIDS formula HF CH3COOH HCN HNO2 H2CO3 F CH3COO name hydrofluoric acid acetic acid vinegar hydrocyanic acid CN NO2 nitrous acid HCO3 carbonic acid soda water H2SO3 sulfurous acid H3PO4 phosphoric acid COOH 2 oxalic acid 2 CO3 HSO3 2 SO3 H2PO4 HPO4 2 3 PO4 H COO 2 COO 2 2 chloride ion bromide ion iodide ion nitrate ion perchlorate ion chlorate ion hydrogen sulfate ion sulfate ion cyanide ion nitrite ion hydrogen carbonate ion carbonate ion hydrogen sulfite ion sulfite ion dihydrogen phosphate ion hydrogen phosphate ion phosphate ion hydrogen oxalate ion oxalate ion the formulas for inorganic mineral acids are usually written with the H first examples include HCl HBr HCN etc HCl g H HCN g H aq Cl aq aq CN aq organic acids contain the carboxyl COOH group nearly all organic acids are weak one example is CH3COOH l CH3COO aq H aq AQUEOUS SOLUTIONS REVERSIBLE REACTIONS a double arrow indicates that the reaction is reversible basically it occurs in both directions weak electrolytes ionize only slightly and reversibly in dilute aqueous solutions all weak inorganic acids ionize in reversible reactions and establish chemical equilibrium this is why they ionize less than 100 AQUEOUS SOLUTIONS STRONG BASES INSOLUBLE BASES AND WEAK BASES bases substances that produce hydroxide ions OH in aqueous solutions strong bases dissociate 100 in water only ions are produced common strong bases know this list all others are weak bases 2 STRONG BASES GROUP 1A formula STRONG BASES GROUP 2A formula name CHAPTER 6 STUDY GUIDE JULY 7 2010 name lithium hydroxide sodium hydroxide potassium hydroxide rubidium hydroxide cesium hydroxide Ca OH 2 Sr OH 2 Ba OH 2 LiOH NaOH KOH RbOH CsOH calcium hydroxide strontium hydroxide barium hydroxide insoluble or sparingly soluble bases ionic compounds that are insoluble in water are not very basic most transition metal hydroxides are insoluble in water do not need to memorize INSOLUBLE BASES formula name Cu OH 2 Fe OH 2 Fe OH 3 Zn OH 2 Mg OH 2 copper II hydroxide iron II hydroxide iron III hydroxide zinc hydroxide magnesium hydroxide often covalent compounds that ionize slightly 1 5 in water weak bases ammonia NH3 is a common weak base NH3 H2O NH4 OH organic amines are similar to ammonia in that they are weak bases the carbonate CO3 2 and bicarbonate HCO3 ions are weak bases CH3NH2 H2O CH3NH3 CH3NHCH3 H2O CH3NH2 OH CH3 OH HCO3 CO3 H2O CO2 OH 2 H2O CO2 2OH AQUEOUS SOLUTIONS SOLUBILITY RULES the solubility rules know these rules 1 common inorganic acids and low molecular weight organic acids are water soluble 2 all common compounds of the group 1A metal ions Li Na K Rb Cs and the ammonium ion NH4 3 common nitrates NO3 are water soluble are water soluble 4 common chlorides Cl are water soluble acetates CH3COO chlorates ClO3 and perchlorates ClO4 exceptions AgCl Hg2Cl2 and PbCl2 these are insoluble common bromides Br and iodides I behave similarly to chlorides Cl as these halides Cl Br and I increase in size the solubilities of their slightly soluble compounds decrease no exceptions listed common fluorides F are water soluble 3 CHAPTER 6 STUDY GUIDE JULY 7 2010 exceptions MgF2 CaF2 SrF2 BaF2 and PbF2 these are insoluble 5 common sulfates SO4 2 are water soluble exceptions PbSO4 BaSO4 and HgSO4 these are insoluble moderately soluble CaSO4 SrSO4 and Ag2SO4 these are moderately soluble 6 common metal hydroxides OH are insoluble exceptions those of the group 1A metals LiOH NaOH KOH RbOH and CsOH and the heavier members of the group 2A metals beginning with Ca OH 2 these are soluble 7 common carbonates CO3 2 phosphates PO4 3 and arsenates AsO4 3 are insoluble these are soluble exceptions those of the group 1A metals and NH4 moderately soluble BaCO3 and MgCO3 these are moderately soluble 8 common sulfides S2 are insoluble exceptions those of the group 1A and group 2A metals and NH4 soluble these are the solubility rules chart know these rules GENERALLY SOLUBLE compounds Na K NH4 fluorides F chlorides Cl bromides Br iodides I sulfates SO4 2 nitrates NO3 chlorates ClO3 acetates CH3COO nitrites NO2 perchlorates ClO4 GENERALLY INSOLUBLE sulfides S2 oxides O2 hydroxides