Solutions Subtopics include: (1) Describing Solutions, (2) Concentrations, (2) Solubility & (3) the Effects of Solutes on Solutions.

Solutions Describing Solutions Define: solution, solute, solvent, electrolyte, suspensions, colloidal dispersions. Explore types of solutions. Separation of Solutions.Concentrations Express the concentrations of solutions in terms of: percent, parts per million, mole fraction, molarity and molality. Solve problems involving the measurements of concentration Solubility Define: miscible, saturated, unsaturated, solubility, supersaturation. Describe Factors that effect solubility. Use “solubility rules” to predict the solubility of an ionic compound in water. Effects of Solutes on Solution Effect of solutes on the boiling point and freezing point of solutions. Solve problems involving freezing point depressions and boiling point elevation (colligative properties). Solve problems involving solutions and chemical equations. Effects of electrolytes on the behavior of the solution.

Describing Solutions Define: solution, solute, solvent, suspensions, colloidal dispersions, distillation filtration & chromatography. Explore types of solutions. Identify homogenous mixtures that are not solutions. Identify the process of separating solutions: distillation, filtration & chromatography.

Aim: What is a Chemical Solution ? Essential Questions: 1.What is a chemical solution? 2.What are some types of chemical solutions? 3.How do we separate chemical solutions? Explain. Key Words: solution, solute, solvent, suspensions, colloidal dispersions, distillation, Filtration, Chromatography.

Name Some Solutions! Q: What are some solutions you have encountered today?

Which One is a Solution? Salt Water Oil Water

Deduction Q: Based on the previous example, how can we describe a solution?

Notes I.Describing Solutions A.Definitions 1.Solution - homogenous mixture of a solute dissolved in a solvent.

Solutes, Solvents & Solutions Solute Solvent Solution

Notes 2. Solute – 3. Solvent – 4. Solution –

What Makes Solutions Homogenous?

Notes B. “Like Dissolves Like” 1.In a solution, all particles attract each other with intermolecular forces of similar strength. i.Polar substances dissolve other polar substances or ionic substances. ii.Nonpolar substances dissolve nonpolar substances.

Gases Given: Particles of different substances must attract each other with intermolecular forces of similar strength in order to form an even distribution, which is a solution. Given: There are no intermolecular forces at work between particles in the gaseous phase Deduction: Do gaseous particles form solutions (an even distribution)? Strong Intermolecular Forces Weak Intermolecular Forces No Intermolecular Forces

Video Dissolving Gasses Dissolving NaCl

Notes 2. In gasses there are essentially no intermolecular forces, therefore all mixtures of gasses are solutions.

Can Solutions Exist Between Particles in Different States (Gas, Liquid, Solid)?

Notes C. States of Matter & Solutions 1.The solute and solvent may be in different phases as long as the particles are evenly distributed amongst each other. i.Ex: Solid NaCl dissolved in liquid water. ii.Ex: Gaseous CO 2 is dissolved in liquid soda.

Solutions Among Various Phases of Matter ExamplePhase of SolutePhase of Solvent Metallic AlloySolid Table salt-waterSolidLiquid Ethyl alcohol-waterLiquid CO 2 -water (Soda)GasLiquid AirGas

How Do We Determine Which Substance is a Solute & Which is the Solvent?

Notes D. Identification of Solutes vs. Solvents 1.If the solute and solvent are in different phases, then solute assumes the solvent’s phase. 2.If the solute and solvent are in the same phase, then the solvent is the one that there is more of.

All solutions are homogenous mixtures, but not all homogenous mixtures are solutions. Can you think of an example of a homogenous mixture that is not a solution?

Suspensions E. Suspensions – suspensions are formed by the physical homogenous mixture of large particles. (Solutions are made by the chemical mixture of smaller particles). 1.Suspensions will settle in time (solutions will not). 2.A light beam passing through a suspension mixture will be visible (in a solution, it will not). 3.Ex. Sand + Water

Colloidal Dispersion F. Colloidal Dispersion – formed when particles larger than those in solution but smaller than those in suspensions are dispersed in a medium 1.The terms dispersed substance vs dispersed medium are used for colloidal dispersion instead of solute and solvent. 2.A colloidal dispersion will not settle. 3.Tyndall effect: a light beam passing through a colloidal dispersion will be clearly visible. 4.Ex. Whipped cream, mayonnaise, paint, gelatin & marshmallow.

Tyndall Effect

Our Chemistry class has run out of salt and we want to make a new batch from collected sea water. How do I separate the salt from the water?

G. Separating Solutions 1.Evaporation Separates dissolved SOLUTE from SOLUTION Ex. Separating salt from water 2. Simple distillation Separates SOLVENT from SOLUTION Ex. Obtaining pure water from sea water 3. Fractional distillation Separates one liquid from a mixture of different liquids using differences in boiling points. Ex. Obtaining alcohol from wine or oxygen/nitrogen from air.

4. Filtration Separates dissolved SOLUTE from SOLUTION Ex. Filtration of blood in kidneys 5. Chromatography Separates mixtures into their constituents by preferential adsorption by a solid. Ex. Separating ink dyes using paper chromatography.Cont’d

Distillation g6U&playnext=1&list=PL73CDD6FFC04D04A4&feature =results_main Filtration Chromatography

Learning Check 1) The solvent is the part of the solution that A. gets dissolved B. does the dissolving C. changes phase 2) Two homogenous mixtures not known as solutions are _______________________ and _______________________. 3) What is a chemical solution? 4) What are some types of chemical solutions? 5) How do we separate chemical solutions? Explain.

Notes Describing & Separating Solutions

I.Describing Solutions A.Definitions 1.Solution - homogenous mixture of a solute dissolved in a solvent. 2.Solute – substance dissolved. 3.Solvent – substance that does the dissolving. 4.Solution – A homogenous mixture composed on tiny particles. B.“Like Dissolves Like” 1.In a solution, all particles attract each other with intermolecular forces of similar strength. i.Polar molecules dissolve other polar molecules and ionic compounds. ii.Nonpolar molecules dissolve nonpolar molecules. 2. In gasses there are essentially no intermolecular forces, therefore all mixtures of gasses are solutions. C. States of Matter & Solutions 1.The solute and solvent may be in different phases as long as the particles are evenly distributed amongst each other. i.Ex: Solid NaCl dissolved in liquid water. ii.Ex: Gaseous CO 2 is dissolved in liquid soda. D. Identification of Solutes vs. Solvents 1.If the solute and solvent are in different phases, then solute assumes the solvent’s phase. 2.If the solute and solvent are in the same phase, then the solvent is the one that there is more of.

E. Suspensions – suspensions are formed by the physical homogenous mixture of large particles. (Solutions are made by the chemical mixture of smaller particles). 1.Suspensions will settle in time (solutions will not). 2.A light bean passing through a suspension mixture will be visible (in a solution, it will not). 3.Ex. Sand + Water F. Colloidal Dispersion – formed when particles larger than those in solution but smaller than those in suspensions are dispersed in a medium 1.The terms dispersed substance vs dispersed medium are used for colloidal dispersion instead of solute and solvent. 2.A colloidal dispersion will not settle. 3.Tyndall effect: a light beam passing through will be clearly visible. 4.Ex. Whipped cream, mayonnaise, paint, gelatin & marshmallow.

G. Seperating Solutions 1. Evaporation – separates dissolved SOLUTE from SOLUTION. i.Ex. Separating salt from water 2. Simple distillation – separates solvent from solution i.Ex. Obtaining pure water from sea water 3. Fractional distillation – separates one liquid from a mixture of different liquids that have different boiling points. i.Ex. Obtaining ALCOHOL from wine or oxygen/nitrogen from air.