Name ___________________Date____________Per_________



Name ___________________Date____________Per_________Review: Sections 12.1-12.3The table below lists characteristics of particles in colloids, solutions, and suspensions. Place a check in the column of each mixture whose particles have a particular characteristic. Characteristics of ParticlesColloidsSolutionSuspensionLess than 1 nm in diameterXBetween 1 – 1000 nm in diameterXLarger than 1000 nm in diameterXSettle out if undisturbedXSeparated by filtrationXScatter lightXXIf a salt water solution is passed through filter paper, does the solute pass through the filter paper? Explain?- Yes, it is a solution and the particles are not small enough to separate out.What about the solvent? Explain?- Yes, because it is all part of the solution.What is the difference between percent by mass and percent by volume?- % mass is a comparison on the mass where %volume is a comparison on the volume.What is the difference between molarity and molality?- Molarity and molality both are a measure of concentrations. However, molarity is based on mols per liter of solution whereas molality is based on the mols per kg of solvent. Molality does not change with changes in temperature.How does 0.5 M and 2.0 M NaCl differ?- 2.0 M is more concentrated that 0.5 M.Explain why water is considered the universal solvent.- Most substances dissolve in water because of its polarity.Percent by mass=mass of soluteX 100mass of solutionM=mol of soluteLiters of solutionS1=S2P1P2m=mol of solutekg of solventPercent by volume=Volume of soluteX 100Volume of solutionXA=nAnA + nB M1V1 = M2V2Problems: Using the necessary formula solve each problem. Remember to show all your work to receive credit.According to a lab procedure, you stir 25.0 g of MgCl2 into 550 mL of water. What is the percent by mass of MgCl2 in the solution?Percent by mass=25.0X 100575Percent by mass = 4.347 4.3%What is the molality of a solution that contains 75.3 g of KCl dissolved in 95.0 g of water?75.3 g KCl1 mol KCl= 1.01 mol KCl 74.55 g KClm=1.010.0950m = 10.6 mHow many moles of BaS would be used to make 1500 mL of a 10.0 M solution?10.0 M=mols1.5 LMols = 15 LWhat is the mole fraction of sulfuric acid in a solution containing 27.3 g sulfuric acid and 72.7 g water?27.3 g H2SO41 mol H2SO4= 0.278 mol H2SO4 98.08 g H2SO472.7 g H2O1 mol H2O= 4.03 mol H2O 18.02 g H2OXA=0.2780.278 + 4.03XA = 0.0645Calculate the percent by volume of a solution created by adding 75 mL of acetic acid to 725 mL of water. Percent by volume=75X 100800Percent by volume = 9.38 9.4%Vinegar contains 5.0 g of acetic acid, in 100.0 mL of solution. What is the molarity of acetic acid in vinegar?5.0 g HC2H3O21 mol HC2H3O2= 0.0833 mol HC2H3O2 60.06 g HC2H3O2M=0.08330.1M = 0.83 M How many grams of LiCl are in 275 g of a 15% aqueous solution of LiCl?15%=Mass of soluteX 100275Mass of solute = 41.25 41 g A chemist needs 15.0 mL of 0.5M NaOH but starts with 3.0 M NaOH. How much 3M NaOH is required for the needed amount of 0.5M solutions? (0.5)(15.0) = (3.0)(V2)V2 = 2.5 mL0.85=S241If 0.85 g of gas at 4.0 atm of pressure dissolves in 1.0 L of water at 25oC, how much will dissolve in 1.0 L of water at 1.0 atm of pressure and the same temperature?S2 = 0.21 g/L50482525908000Use the following graph to answer questions. According to the solubility curve, how many grams of potassium chloride can be dissolved at 30?C?- About 36 gramsDetermine if the following solution is supersaturated, saturated or unsaturated: 80 grams of sodium nitrate at 40?C.- UnsaturatedIf 60 grams of potassium nitrate is dissolved in 100 g of water at 50?C, how many more grams must be added to produce a saturated solution of potassium nitrate?- About 20 grams If potassium iodide is cooled from 15?C to 0?C, how much solid potassium iodide will come out of solution?- About 12 gramsUsing the graph above:What is the solubility of KCl at 5C?About 28 gramsWhat is the solubility of KCl at 25C?About 34 gramsWhat is the solubility of Ce2(SO4)3 at 10C?About 13 gramsWhat is the solubility of Ce2(SO4)3 at 50C?About 6 gramsAt 90C, you dissolved 10 g of KCl in 100. g of water. Is this solution saturated or unsaturated? How do you know?- Unsaturated, because it is below the line on the graph.A mass of 100 g of NaNO3 is dissolved in 100 g of water at 80?C.Is the solution saturated or unsaturated? UnsaturatedAs the solution is cooled, at what temperature should solid first appear in the solution? Explain.- It would have to cool to something below 60oCUse the graph to answer the following two questions:Which compound is most soluble (hold the most solute) at 20 ?C? KIWhich is the least soluble (holds the least amount of solute) at 20 ?C? KClO3Which substance on the graph is least soluble at 10C? KClO3A mass of 80 g of KNO3 is dissolved in 100 g of water at 50 ?C. The solution is heated to 70?C. How many more grams of potassium nitrate must be added to make the solution saturated? Explain your reasoning.- About 48 more grams. As the solution is heated it allows more solute to be dissolved.Types of SolutionsOn a solubility curve, the lines indicate the concentration of a Saturated solution - the maximum amount of solute that will dissolve at that specific temperature.Values on the graph Under a curve represent unsaturated solutions - more solute could be dissolved at that temperature.Values on the graph Above a curve represent super saturated solutions - more than the maximum amount of solute is dissolved at that temperature.SolutionSaturated, Supersaturated, or Unsaturated?If unsaturated: How much more solute can dissolve in the solution? a solution that contains 70g of NaNO3 at 30°C (in 100 mL H2O)UnsaturatedAbout 23 more gramsa solution that contains 50g of KClO3 at 60°C (in 100 mL H2O)SupersaturatedNonea solution that contains 50g of NH4Cl at 50°C (in 100 mL H2O)SaturatedNone, it is at the most that can dissolve.a solution that contains 20g of KClO3 at 50°C (in 100 mL H2O)SaturatedNone, it is at the most that can dissolve.a solution that contains 70g of KI at 0°C (in 100 mL H2O)UnsaturatedAbout 60 more gramsLabel the following solutions as saturated, unsaturated, or super saturated. If unsaturated, write how much more solute can be dissolved in the solution. ................
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