Solution: a homogeneous mixture of two or more substances Solution: a homogeneous mixture of two or more substances Solute: substance that is dissolved.

Solution: a homogeneous mixture of two or more substances Solution: a homogeneous mixture of two or more substances Solute: substance that is dissolved Solute: substance that is dissolved Solvent: substance in which solute is dissolved Solvent: substance in which solute is dissolved Aqueous Solutions: water is solvent (aq). Aqueous Solutions: water is solvent (aq). Solutions: Review of Basic Terms

Solubility: (see Table G) how much solute that can be dissolved in a certain amount of solvent at a given temperature and pressure. Solubility: (see Table G) how much solute that can be dissolved in a certain amount of solvent at a given temperature and pressure. Saturated solution Saturated solution Unsaturated solution Unsaturated solution Supersaturated solution Supersaturated solution Excess solid solute will precipitate out of solution when conditions change Excess solid solute will precipitate out of solution when conditions change Gases decrease in solubilty with an increase in temp. Gases decrease in solubilty with an increase in temp. Solids and liquids increase in solubility with an increase in temp. Solids and liquids increase in solubility with an increase in temp.

Soluble vs. Insoluble Ionic Salts (Table F) Soluble vs. Insoluble Ionic Salts (Table F) Indicates if relatively large or small quantity of solute will dissolve in water Indicates if relatively large or small quantity of solute will dissolve in water If amount is really small, salt is called “insoluble” If amount is really small, salt is called “insoluble”

How can you tell how many solute particles are dissolved in solution? How can you tell how many solute particles are dissolved in solution? Methods of Indicating Concentration

Molarity Indicates how many MOLES of solute are dissolved in a certain liters of solution. Molarity = Moles of solute Liters of solution Ex: A 2M solution (2 “molar”) contains 2 moles of solute per liter of solution Note: The molarity definition is based on the volume of the solution, NOT the volume of water.

Ex. How many moles of HCl are present in 3.0 L of a 4.0 M solution? Molarity Problem #mol = given mass GFM M = mol L 4.0 M = x 3.0 L _____ 1 X = 12 mol

You try it… A 3.0 M HCl (aq) solution contains a total of (1) 3.0 grams of HCl per liter of water (2) 3.0 grams of HCl per mole of solution (3) 3.0 moles of HCl per liter of solution (4) 3.0 moles of HCl per mole of water

You try it… Which sample of HCl (aq) contains the greatest number of moles of solute particles? (1) 1.0 L of 2.0 M HCl (aq) (2) 2.0 L of 2.0 M HCl (aq) (3) 3.0 L of 0.50 M HCl (aq) (4) 4.0 L of 0.50 M HCl (aq)

You try it… How many total moles of KNO 3 must be dissolved in water to make 1.5 liters of a 2.0 M solution? (1) (1) 0.50 mol (2) (2) 2.0 mol (3) (3) 3.0 mol (4) (4) 1.3 mo

You may have to find out how many moles of solute you have from the grams given first. You may have to find out how many moles of solute you have from the grams given first. # moles = grams solute given gram formula mass Or use this formula if grams are given: Grams solute = L x M x GFM solute Link to videos showing how to solve several problem types: Link to videos showing how to solve several problem types: http://www.kentchemistry.com/links/Math/molarity.htm

Ex What is the molarity of the solution with 117 g of NaCl dissolved in 500. mL of water? M = mol L x = ________ x = 4.00 mol L x = 4.00 M Or 117g =.5 Liters x M x 58.5g/mol x = 2.00 mol Molarity Problem 2.00 mol 0.500 L #mol = given mass GFM x = 58.5 g/mol 117 g “molar”

Ex. How many grams of Ba(OH) 2 are needed to prepare 2.0 liters of a 2.5  10 -4 M solution? M = mol L 2.5  10 -4 M = _____ 2.5  10 -4 M = _____ x = 0.00050 mol OR Grams = 2.0 Liters x 2.5  10 -4 M x 171 g/mol x = 0.086 g Molarity Problem x 2.0 L #mol = given mass GFM 0.00050 mol = _________ 171 g/mol x _________ 1 __________ 1

You try it… What is the molarity of 1.5 liters of an aqueous solution that contains 52 grams of lithium fluoride, LiF, (gram-formula mass =26 grams/mole)? (1) 1.3 M (2) 3.0 M (3) 2.0 M (4) 0.75 M

You try it… What is the Molarity of a solution containing 20 grams of NaOH in 500 milliliters of solution? (1) 1 M (2) 0.04 M (3) 2 M (4) 0.5 M

Parts Per Million Parts per Million (ppm) is the ratio of the number of grams of solute for every one million grams of solution. Parts per Million (ppm) is the ratio of the number of grams of solute for every one million grams of solution. Remember: Grams “Solution” = Grams Solute + Grams Solvent 1 ml of H 2 O = 1 gram

Parts per Million Example Ex. What is the ppm of NaCl in the solution with 117 g of NaCl dissolved in 500. mL of water? ppm = g solute x 1000000 ppm = g solute x 1000000 g sol’n g sol’n x = ______ x 1000000 117 g 617 g x = 190000 ppm

Parts per Million Example Ex.What is the number of ppm of C 2 H 4 (OH) 2 in the solution with 55.5 g (50.0 mL) of liquid C 2 H 4 (OH) 2 dissolved in 150.0 mL of water ? ppm = g solute x 1000000 g sol’n g sol’n x = __________ x 1000000 55.5 g 205.5 g x = 270000 ppm

You try it… An aqueous solution has 0.0070 gram of oxygen dissolved in 1000. grams of water. Calculate the dissolved oxygen concentration of this solution in parts per million.

You try it… If 0.025 gram of Pb(NO 3 ) 2 is dissolved in 100. grams of H 2 O, what is the concentration of the resulting solution, in parts per million? (1) 2.5 × 10 –4 ppm (2) 2.5 ppm (3) 250 ppm (4) 4.0 × 10 3 ppm

You try it… What is the total mass of solute in 1000. grams of a solution having a concentration of 5 parts per million? (1) 0.005 g (2) 0.05 g (3) 0.5 g (4) 5 g

Percent Solution Same idea as parts per milliion, Same idea as parts per milliion, But instead think of “parts” solute in 100 parts solution. But instead think of “parts” solute in 100 parts solution. % Solution = grams solutex 100 grams solution grams solution

Percent Solution Problems Ex: What is the % solution if 5g glucose is dissolved in 100g water? Ex: If you 500g have a 2% salt solution how many grams of solute does it contain? Ex: If you have a 15% salt solution, how many ppm is the solution?

Molarity and Dilution Problems deal with adding or removing water from a solution and determining the new molarity. Problems deal with adding or removing water from a solution and determining the new molarity. Remember the #moles of solute particles doesn’t change! Remember the #moles of solute particles doesn’t change! InitialFinal M 1 x V 1 = M 2 x V 2

Dilution Examples Ex: If 500 ml of a 2M solution of glucose is diluted with 1000ml of water, what is the new molarity of the solution? Ex: If 500 ml of a 2M solution of glucose is diluted with 1000ml of water, what is the new molarity of the solution? Ex: If 250ml of a 1.2M solution is heated and 100ml of water evaporates off, what is new concentration? Ex: If 250ml of a 1.2M solution is heated and 100ml of water evaporates off, what is new concentration?

Have to do with the concentration of particles of solute dissolved in solvent. Have to do with the concentration of particles of solute dissolved in solvent. Colligative means “of the collection” Colligative means “of the collection” When any solute gets dissolved in a solvent three things occur: When any solute gets dissolved in a solvent three things occur: Vapor Pressure is Reduced Vapor Pressure is Reduced Boiling Point is Elevated Boiling Point is Elevated Freezing Point is Depressed Freezing Point is Depressed Colligative Properties of Solutions

Fewer solvent particles are at the solutions surface so less evaporates Fewer solvent particles are at the solutions surface so less evaporates Due to solute/solvent attractions, less solvent is able to escape from liquid phase to become vapor. Due to solute/solvent attractions, less solvent is able to escape from liquid phase to become vapor. This results in a decrease in vapor pressure. Vapor Pressure Reduction

All pure liquids have a normal boiling point. Boiling occurs when: Vapor pressure = atm. pressure When solute gets dissolved, VP is reduced and a solution needs to reach a higher temp. before VP = atm. pressure The HIGHER the concentration, the higher the BP will be. Boiling Point Elevation

Example: Radiator Coolant Coolant is added to the water in a car’s radiator which raises the water’s boiling point. Coolant is added to the water in a car’s radiator which raises the water’s boiling point.

All pure liquids have a normal freezing point. All pure liquids have a normal freezing point. Solute particles make it harder for liquid solvent to form a crystalline lattice as a solid. Solute particles make it harder for liquid solvent to form a crystalline lattice as a solid. It requires a lower temp. to freeze It requires a lower temp. to freeze The higher the concentration of solute particles, the lower the freezing point will be. The higher the concentration of solute particles, the lower the freezing point will be. Freezing Point Depression https://www.youtub e.com/watch?v=T BkNstDmtj0

Freezing Point Depression

Example: Salt on Sidewalks Rock salt or super melt are sprinkled on icy sidewalks which lowers the ice’s freezing point. Rock salt or super melt are sprinkled on icy sidewalks which lowers the ice’s freezing point. How does salt melt ice? https://www.youtube.com/watch?v=JkhWV2uaHaA

Ex: Making Ice Cream When making ice cream, salt is added to the ice surrounding the canister. The added salt lowers the ice’s freezing point making the canister colder than 0 o C! When making ice cream, salt is added to the ice surrounding the canister. The added salt lowers the ice’s freezing point making the canister colder than 0 o C!

Ex: Plane De-Icer, Liquor in Freezer Airplane’s are de-iced with ethylene glycol. Airplane’s are de-iced with ethylene glycol. Vodka or Gin in freezer stays liquid. Vodka or Gin in freezer stays liquid.

Conductivity of Solutions If mobile ions are present in solution the solution will conduct electricity. If mobile ions are present in solution the solution will conduct electricity. Ex: NaCl (aq) Ex: NaCl (aq) The greater the concentration of these ions, the more it will conduct The greater the concentration of these ions, the more it will conduct Substances that break apart readily to form ions in solution are called strong electrolytes Substances that break apart readily to form ions in solution are called strong electrolytes

Electrolytes & Nonelectrolytes ELECTROLYTES: conduct in solution. Ex: Soluble ionic compounds and “strong” acids and bases Ex: Soluble ionic compounds and “strong” acids and bases NONELECTROLYTES: do not conduct in solution. Organic compounds are usually nonelectrolytes. Organic compounds are usually nonelectrolytes. Ex: Sugars and alcohols Ex: Sugars and alcohols Electrolytes provide free moving IONS to water whereas nonelectrolytes do not provide free moving IONS to water. + + + ― ― ― Electrolyte dissolved in Water + - + - + - + - Nonelectrolyte dissolved in Water

Dissociation & Colligative Properties THE DISSOCIATION FACTOR: (“i” value) Is equal to the number of ion particles the solute will break apart into in solution. Is equal to the number of ion particles the solute will break apart into in solution. Nonelectrolytes do not ionize so “i” is always equal to 1. Nonelectrolytes do not ionize so “i” is always equal to 1. Electrolytes have an “i” value equal to the total number of ions it will create in solution. Electrolytes have an “i” value equal to the total number of ions it will create in solution.

Dissociation and Colligative Properties This will effect COLLIGATIVE PROPERTIES This will effect COLLIGATIVE PROPERTIES REMEMBER: the more total particles in solution, the greater the colligative “effect”. REMEMBER: the more total particles in solution, the greater the colligative “effect”. A mole of an electrolyte (like a salt) in water would have a greater affect on BP/VP/FP than a mole of a nonelectrolyte A mole of an electrolyte (like a salt) in water would have a greater affect on BP/VP/FP than a mole of a nonelectrolyte It breaks apart in solution making more particles!! It breaks apart in solution making more particles!!

Nonelectrolyte in Solution Glucose is a sugar which is a nonelectrolyte. Glucose is a sugar which is a nonelectrolyte. When dissolved in water, glucose does NOT form ions. When dissolved in water, glucose does NOT form ions. Thus a 1.00 mole of glucose dissolved in water will have 1.00 mole of dissolved particles. Thus a 1.00 mole of glucose dissolved in water will have 1.00 mole of dissolved particles. C 6 H 12 O 6(s)  C 6 H 12 O 6(aq) C 6 H 12 O 6(s)  C 6 H 12 O 6(aq) C 6 H 12 O 6 O HH O H H O HH O H H O HH O HH O H H O H H O H H O H H O HH O HH O HH O HH O HH O H H O HH O H H O HH O HH O H H O H H O H H O H H O HH O HH O HH O HH [i = 1]

Electrolyte in Solution Sodium chloride is a salt which is an electrolyte. Sodium chloride is a salt which is an electrolyte. When dissolved in water, sodium chloride does form ions. When dissolved in water, sodium chloride does form ions. Thus a 1.00 mole of sodium chloride dissolved in water will have 2.00 moles of dissolved particles. Thus a 1.00 mole of sodium chloride dissolved in water will have 2.00 moles of dissolved particles. NaCl(s)  Na + (aq) + Cl - (aq) NaCl(s)  Na + (aq) + Cl - (aq) Na + Cl - Cl - Na + O HH O H H O HH O H H O HH O HH O H H O H H O H H O H H O HH O HH O HH O HH O HH O HH O H H O HH O H H O H H O H H O H H O HH O HH O HH Na + Cl - Na + Cl - O HH O HH O H H [i = 2]

More Particles = More Effect! Which of the following two solutions has more dissolved particles? Which of the following two solutions has more dissolved particles? Which of the following two solutions will have a lower freezing point? Which of the following two solutions will have a lower freezing point? 4.0 M C 6 H 12 O 6 4.0 M NaCl 4.0 M C 6 H 12 O 6 4.0 M NaCl O HH O HH O H H O HH O H H O H H O H H O H H O HH O HH O HH Na + Cl - Na + Cl - O HH O HH O H H O HH O H H O HH O H H O HH O HH O H H O H H O H H O H H O HH O HH O HH O HH C 6 H 12 O 6 The NaCl solution!

Electrolytes & Nonelectrolytes Ex.3) Classify the each following solute formulas as a(n) acid, base, salt, sugar, or alcohol and then give its ideal “i” value. (a) KCl________“i” = _____ (b) HCl ________“i” = _____ (c) Ba(OH) 2 ________“i” = _____ (d) CH 3 OH________“i” = _____ (e) C 6 H 12 O 6 ________“i” = _____ (f) H 2 SO 4 ________“i” = _____ (g) CH 3 COOH________“i” = _____ salt 2 acid base alcohol sugar 2 3 1 1 3 2

Electrolytes & Nonelectrolytes Ex.4) Write the dissolving equations for the substances in question #3. (a) _______________________________________ (b) _______________________________________ (c) _______________________________________ (d) _______________________________________ (e) _______________________________________ (f) _______________________________________ (g) _______________________________________ KCl (s) KCl+ 1+ (aq) 1- (aq) HCl (g) H 1+ (aq) +Cl 1- (aq) Ba(OH) 2(s) Ba 2+ (aq) +2 OH 1- (aq) CH 3 OH ( l ) CH 3 OH (aq) H2OH2O H2OH2O H2OH2O H2OH2O C 6 H 12 O 6(s) C 6 H 12 O 6(aq) H2OH2O H 2 SO 4(s) H2OH2O 2 H 1+ (aq) +SO 4 2- (aq) CH 3 COOH (s) H2OH2O CH 3 COO 1- (aq) +H 1+ (aq)

Electrolytes & Nonelectrolytes Ex.5) Generally (organic / inorganic) _________. substances are nonelectrolytes. Ex.6) Pure water is a _____________ of electricity. Ex.7) Ionic compounds do not conduct an electric current when in the ______ phase. Ex.8) The formation of free moving of the charged particles as a solute dissolves in water permits the solution to _________ an electric current. Ex.9) Substances that do not conduct an electric current when dissolved in water are called _______________. Ex.10) Which of the following substances will conduct electricity the least when added to water? (1) C 2 H 5 COOH (3) C 6 H 12 O 6 (1) C 2 H 5 COOH (3) C 6 H 12 O 6 (2) Ca(OH) 2 (4) ZnSO 4 organic nonconductor solid conduct nonelectrolytes acid base sugar salt

Colligative Properties of Solutions Ex.(1) Pure water will boil at a ____________________ temperature than saltwater. temperature than saltwater. Ex.(2) Pure water will freeze at a ____________________ temperature than saltwater. temperature than saltwater. Ex.(3) Which 1.0 M aqueous solution would have the lowest freezing point? freezing point? (1) NaCl (2) HCl (3) KCl (4) CaCl 2. (1) NaCl (2) HCl (3) KCl (4) CaCl 2. Ex.(4) If some ethylene glycol - C 2 H 4 (OH) 2 is dissolved in water, then the resulting solution will freeze at a water, then the resulting solution will freeze at a _______________ temperature than normal. _______________ temperature than normal. lower higher lower

Colligative Properties of Solutions Ex.(5) If some ethylene glycol - C 2 H 4 (OH) 2 is dissolved in water, then the resulting solution will boil at a in water, then the resulting solution will boil at a _______________ temperature than normal. _______________ temperature than normal. Ex.(6) Why will a bottle of wine (12% alc. by vol.) or beer (3% alc. by vol.) freeze when placed in the freezer (3% alc. by vol.) freeze when placed in the freezer but a bottle of gin (47% alc. by vol.) will not? but a bottle of gin (47% alc. by vol.) will not? _________________________________________ _________________________________________ higher

You Try It… Compared to pure water, an aqueous solution of calcium chloride has a (1) higher BP and higher FP (2) higher BP and lower FP (3) lower BP and higher FP (4) lower BP and lower FP

You Try It… Compared to a 2.0 M aqueous solution of NaCl at 1 atmosphere, a 3.0 M aqueous solution of NaCl at 1 atmosphere has a (1) lower boiling point and a higher freezing point (2) lower boiling point and a lower freezing point (3) higher boiling point and a higher freezing point (4) higher boiling point and a lower freezing point

You Try It… Which solution has the highest boiling point at standard pressure? (1) 0.10 M KCl(aq) (2) 0.10 M K 2 SO 4 (aq) (3) 0.10 M K 3 PO 4 (aq) (4) 0.10 M KNO 3 (aq)

Honors Calculations Vapor Pressure Reduction: Vapor Pressure Reduction: Mole Solvent x Normal VP at that temp. = VP solution Moles Solution Boiling Point Elevation: ΔT b = k b x i x m Boiling Point Elevation: ΔT b = k b x i x m K b for water = = 0.52 C°/m K b for water = = 0.52 C°/m Freezing Point Reduction: ΔT f = k f x i x m Freezing Point Reduction: ΔT f = k f x i x m K f for water = 1.86 C°/m K f for water = 1.86 C°/m Use molality values here

Honors Calculations Molality = moles solute kg of solvent Only formula that deals with volume of “solvent” not “solution”. 1m solution = 1 “molal” solution 1000g = 1kg, 1g H 2 O = 1 ml If grams in problem use: Grams solute = kg solvent x m x GFM solute

Do Now Honors Packet pages 1-5 Honors Packet pages 1-5

Solution: a homogeneous mixture of two or more substances Solution: a homogeneous mixture of two or more substances Solute: substance that is dissolved.

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Solution: a homogeneous mixture of two or more substances Solution: a homogeneous mixture of two or more substances Solute: substance that is dissolved.

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