CHEM 105 1nd Edition Lecture 7 Outline of Last Lecture • A solution is a mixture in which one substance.• The solute, is evenly dispersed in a larger quantity of another substance, the solvent.• Molarity (M): the number of moles of solute in one liter of solution.• The molar concentration of any solute is represented by the formula of the solute placed in square brackets[ ].• [NaCl] = the concentration of sodium chloride in mol/L.Outline of Current Lecture • Ionic compounds are strong electrolytes.• Molecular compounds that are not acids are non-electrolytes.• Acids are molecular compounds that transfer hydrogen ions to water to make hydronium ions (see page 148).• Strong acids completely transfer the available hydrogen ions. They are strong electrolytes.• There are six strong acids. You will need to know these six. There is a table of them somewhere in chapter 4. Find it!• Weak acids only partially transfer the available hydrogen ions. They are weak electrolytes.• A base accepts H from another substance. Hydroxide salts are strong bases (strongelectrolytes). +• Other bases (ammonia and carbonate, for example) are weak bases. They accept less H than + there are base molecules. They are weak electrolytes.Current LectureQ: Classify the following as strong electrolytes, weak electrolytes or nonelectrolytes:CH3OH nonelectrolytes KOH StrongNaCl Strong FeCl3 StrongHNO3 Strong HCN WeakC6H12O6 nonelectrolytes CaBr2 StrongNH3 Weak C2H6O2 Nonelectrolytes• A titration (section 4.6) is applied stoichiometry:Q: 33.06 mL of a 0.362 M KOH solution are required to neutralize 25.00 mL of a H2SO4solution.2 KOH(aq) + H2SO4(aq) ------> K2SO4(aq) + 2H2O(I) Calculate the concentration of the Sulfuric acid soultion. A: 0.03306L x 0.362 mol KOH/ 1L =0.01196772 mol KOH0.01196772 mol NaOH x 1mol H2So4 = 0.059836 mol H2So40.059838 mol/0.02500L = 0.2393 mol/L • A “Molecular” equation is a standard chemical equation.• Overall Ionic Equation - all ionic compounds in solution are shown as dissociated ions.• Net Ionic Equation - only the ions that actually participate in the reaction are shown.• Write molecular, complete ionic, and net ionic equations for the neutralization reaction from the titration.Molecular equation: 2KOH(aq) + H2SO4 (aq) -----> K2SO4 (aq) + 2H2O(l)Overall ionic equation: 2K+(aq) + 2OH-(aq) + 2H+(aq) + SO4-(aq) ----> 2H2O(l) +2K+(aq) +SO4(aq)Net ionic equation:2eH-(aq) + 2H-(aq) ----> 2H2O(l)H+(aq) + OH-(aq) -----> H2O(l) Q: Write molecular equations and net ionic equations for the following reactions:• strontium hydroxide and hydrobromic acidSr(OH)2(aq) + 2HBr(aq) -----> 2H2O(l) + SrBr2H+(aq) + OH-(aq) ----> H2O(l)• sodium carbonate and hydrochloric acidNa2CO3(aq) + 2HCl(aq) -----> 2NaCl(aq) + H2O(l) + CO3(aq)CO3- + 2H+(aq) ----> H2O(l) +
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