新编SolutionConcentrationCurrituckCountySchools：溶液浓度柯里塔克县学校课件

1、新编SolutionConcentrationCurrituckCountySchools：溶液浓度柯里塔克县学校新编SolutionConcentrationCurrituReviewA solution is a homogeneous mixture.The solvent is the major component of the solution.The solute is the minor component and active ingredient.A saturated solution holds the maximum amount of solute that is

2、theoretically possible for a given temperature.ReviewA solution is a homogeneHow would you describe this picture?How would you describe this piSolution ConcentrationIs one glass of tea stronger than the other?Whats true about the “stronger” glass of tea?How much tea does it have in it compared to th

3、e other glass?Solution ConcentrationIs one gSolution ConcentrationConcentration a ratio comparing the amount of solute to the amount of solution.Many ways of expressing concentration:% by weight (% w/w)% by volume (% v/v)parts per million (ppm) or parts per billion (ppb) for very low concentrationsm

4、olality (m)Molarity (M)Solution ConcentrationConcentrConcentrated vs. DiluteThe words “concentrated” and “dilute” are opposites.EX: The dark tea is more concentrated than the light tea.EX: The light tea is more dilute than the dark tea.Concentrated vs. DiluteThe worConcentrated vs. DiluteConcentrate

5、d solutionDilute solution= solute particlesConcentrated vs. DiluteConcentPercent by Weight% by weight (% w/w)What is the % w/w of a solution if 3.00 grams of NaCl are dissolved in 17.00 g of water?mass of solute = 3.00 gmass of solution = 3.00 g + 17.00 g = 20.00 g(3.00 g / 20.00 g) x 100% = 15.0% w

6、/wPercent by Weight% by weight (Percent by Volume% by volume (% v/v)What is the % v/v of a solution if 20.0 mL of alcohol are dissolved in 50.0 mL of solution?volume of solute = 20.0 mLvolume of solution = 50.0 mL(20.0 mL / 50.0 mL) x 100% = 40.0%Percent by Volume% by volume (MolarityMolarity (M)UNI

7、TS: mol/L or Molar (M)Example: 0.500 mol/L = 0.500 MMolarityMolarity (M)MolarityWhat is the Molar concentration of a soln if 20.0 grams of KNO3 (MM = 101.11 g/mol) is dissolved in enough water to make 800. mL?Convert g of KNO3 to mol of KNO3Convert mL to LMolarityWhat is the Molar concMolarityWhat i

8、s the Molar concentration of a soln if 0.198 mol KNO3 is dissolved in enough water to make 0.800 L?MolarityWhat is the Molar concMolarityWhat is the Molar concentration of a soln if 10.5 grams of glucose (MM = 180.18 g/mol) is dissolved in enough water to make 20.0 mL of soln?Convert g of glucose to

9、 mol of glucose.Convert mL to L.MolarityWhat is the Molar concMolarityWhat is the Molar concentration of a soln if 0.0583 mol of glucose is dissolved in enough water to make 0.0200 L of soln?MolarityWhat is the Molar concCalculating GramsHow many grams of KI (MM = 166.00 g/mol) are needed to prepare

10、 25.0 mL of a 0.750 M solution?Convert mL to L.Solve for moles.moles of KI = 0.750 M x 0.0250 L = 0.0188 mol KICalculating GramsHow many gramCalculating GramsHow many grams of KI (MM = 166.00 g/mol) are needed to prepare 25.0 mL of a 0.750 M solution?Convert 0.0188 mol KI to grams.Calculating GramsH

11、ow many gramCalculating GramsHow many grams of HNO3 (MM = 63.02 g/mol) are present in 50.0 mL of a 1.50 M soln?Convert mL to L.50.0 mL = 0.0500 LSolve for moles:moles = (1.50 M)(0.0500 L) = 0.0750 mol HNO3Convert 0.0750 mol HNO3 to grams:0.0750 mol HNO3 = 4.73 g HNO3Calculating GramsHow many gramDil

12、utionDilute (verb) - to add solvent to a solution.Decreases soln concentration.M1V1 = M2V2M1 = initial conc.V1 = initial volumeM2 = final conc.V2 = final volumeAssumes no solute is added.DilutionDilute (verb) - to addDilutionStock SolutionImpracticallyHigh ConcentrationUsable SolutionAdd H2OQuestion

13、 for Consideration: Why do you think chemical supply companies typically sell acids (and other solutions) in extremely high concentrations when it would be safer to ship more dilute solutions?DilutionStock SolutionUsable SDilutionTo what volume should 40.0 mL of 18 M H2SO4 be diluted if a concentrat

14、ion of 3.0 M is desired?What do we want to know?V2What do we already know?M1 = 18 MV1 = 40.0 mLM2 = 3.0 M(18 M)(40.0 mL) = (3.0 M)V2720 M*mL = (3.0 M)V2V2 = 240 mLDilutionTo what volume should DilutionYou are asked to prepare 500. mL of 0.250 M HCl, starting with a 12.0 Molar stock soln. How much st

15、ock should you use?What do we want to know?V1 What do we already know?M1 = 12.0 MM2 = 0.250 MV2 = 500. mL(12.0 M) V1 = (0.250 M)(500. mL)(12.0 M) V1 = 125 M*mLV1 = 10.4 mLDilutionYou are asked to prepaTo how much water should you add 20.0 mL of 5.00 M HNO3 to dilute it to 1.00 M?What do we want to k

16、now?How much water to add. (V2 - V1)What do we already know?M1 = 5.00 MV1 = 20.0 mLM2 = 1.00 M(5.00 M)(20.0 mL) = (1.00 M) V2 100. M*mL = (1.00 M) V2 V2 = 100. mLWater added = 100. mL - 20.0 mL = 80. mLDilutionTo how much water should you aColligative Properties Colligative properties are properties

17、 of solutions that are affected by the number of particles but not the identity of the soluteColligative Properties ColligaBoiling Point Elevation: A Colligative PropertyBoiling point elevation is the temperature difference between a solution and pure solventThe value of the boiling point elevation is directly proportional to molality, meaning the greater the number of solute particles, the greater the elevationBoiling Point Elevation: A ColFreezing Point Depression: A Coll