CHEM 105 1nd Edition Lecture 6 Chapter 4 : Solution Chemistry and the HydrosphereOutline of Last Lecture • Theoretical Yield• Empirical Formula• Formula unit• Molecular FormulaOutline of Current 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.Current LectureQ: What mass of iron(III) chloride is required to produce 250.0mL of a solution that is 0.5000M iron(III) chloride?A: FeCl355.85 g/mol+ 3x35.45 g/mol= 162.20 g/mol250.0 ml x1L/1000mL x0.5000mol/1L x162.20g/ 1mol= 20.275g Q: If 75.00g of sodium sulfate is dissolved in water and the final volume of the solution is adjusted to 500.0mL, what is the concentration of sodium sulfate [Na2So4]?A: 2x22.99g/mol +32.07g/mol +4x16.00g/mol =142.05g/mol75.00g x1mol/142.05g =0.527983 mol Na2So40.527983mol/0.5000L =1.056M• What is the concentration of sodium ions?[Na+]= 1.056M Na2So4 x2mol Na+/1mol Na2So4 =2.112M• What is the concentration of sulfate ions?[SO4-]= 1.056MQ: If 35.40 mL of a 2.100 M solution of copper(II) sulfate are diluted to 750.00mL, what is the concentration of the new solution?A: 0.03574 L x2.100 mol CaSo4/ 1L =0.07434mol0.07434 L/mol/0.75 mol =0.0912MQ: What volume of 12.1M HCl is required to make 2.00 L of a 0.150M solution?A: M= m/v -----> M.v =m ------> V= m/M2.00L x0.150 mol HCl/ 1L =0.300 mol HCl0.300 mol x1L/12.1 mol =0.0247934 L24.8 ml of the 12.1M HCl are required Q: What volume of a 3.84 M HCl solution is required to completely consume 8.45 g of zinc metal according to the equation:Zn(s) +2HCl(aq) -----> ZnCl2(aq) +H2(g) A: 8.45g x1mol Zn/65038g =0.1292444 mol Zn0.1292444mol Zn x2mol HCl/1mol Zn =0.25888 mol HCl0.2584888 mol x1L/3.84mol =0.0673148L67.3 mL is required Q: Write equations for what happens when the following substances are dissolved in water: • Sodium sulfateNa2SO4(s) -----> 2Na+(aq) + SO4-(aq)• ethylene glycol (C2H6O2)C2H6O2(L) -----> C2H6O2(aq) • Acetic acidHC2H3O2(L) -----> H+(aq)
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