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Modern Chemistry Chapter 12- Solutions

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Page 1: [PPT]Modern Chemistry Chapter 12- Solutions - Licking … Chemistry Chapter 12... · Web viewModern Chemistry Chapter 12-Solutions Section 1- Types of Mixtures Solutions are homogeneous

Modern Chemistry Chapter 12-Solutions

Page 2: [PPT]Modern Chemistry Chapter 12- Solutions - Licking … Chemistry Chapter 12... · Web viewModern Chemistry Chapter 12-Solutions Section 1- Types of Mixtures Solutions are homogeneous

Section 1- Types of Mixtures• Solutions are

homogeneous mixtures of two or more substances in a single phase.

– Soluble describes a substance as capable of being dissolved.

– Solvent is the dissolving medium in a solution.

– Solute is the substance that is dissolved in a solution.

Page 3: [PPT]Modern Chemistry Chapter 12- Solutions - Licking … Chemistry Chapter 12... · Web viewModern Chemistry Chapter 12-Solutions Section 1- Types of Mixtures Solutions are homogeneous

Types of Solutions• Solutions can be in

any of the three common physical states.

solid- a mixture of metals called an alloy

liquid- salt water, sugar water, Kool-Aid…

gas- the atmosphere

Page 4: [PPT]Modern Chemistry Chapter 12- Solutions - Licking … Chemistry Chapter 12... · Web viewModern Chemistry Chapter 12-Solutions Section 1- Types of Mixtures Solutions are homogeneous

Suspensions & Colloids• A suspension has

large particles that settle out of a solvent. eg. muddy water

• A colloid has intermediate size particles. Also called an emulsion or a foam.

Page 5: [PPT]Modern Chemistry Chapter 12- Solutions - Licking … Chemistry Chapter 12... · Web viewModern Chemistry Chapter 12-Solutions Section 1- Types of Mixtures Solutions are homogeneous

Solutes: electrolytes vs. nonelectrolytes

• An electrolyte is a substance that dissolves in water to give a solution that conducts electricity.

• A nonelectrolyte is a substance that dissolves in water to give a solution that does NOT conduct electricity.

• Do section review questions #1, #2, & #6 on page 406.

Page 6: [PPT]Modern Chemistry Chapter 12- Solutions - Licking … Chemistry Chapter 12... · Web viewModern Chemistry Chapter 12-Solutions Section 1- Types of Mixtures Solutions are homogeneous

Section 2- The Solution Process

• Factors that affect the rate of solution (how quickly a substance dissolves):– Any process that increases the number of

contacts between the solvent and the solute will increase the solution rate.

• increasing the surface area of the solute• agitating (shaking or stirring) the solution• heating the solvent

Page 7: [PPT]Modern Chemistry Chapter 12- Solutions - Licking … Chemistry Chapter 12... · Web viewModern Chemistry Chapter 12-Solutions Section 1- Types of Mixtures Solutions are homogeneous

Solutions• Solution equilibrium is the physical state in which the

opposing processes of dissolution and crystallization occur at equal rates.

• A saturated solution contains the maximum amount of dissolved solute.

• An unsaturated solution contains less than the maximum amount of dissolved solute.

• A supersaturated solution contains more dissolved solute than a saturated solution.

Page 8: [PPT]Modern Chemistry Chapter 12- Solutions - Licking … Chemistry Chapter 12... · Web viewModern Chemistry Chapter 12-Solutions Section 1- Types of Mixtures Solutions are homogeneous

Solubility• Solubility is a measurement of how much solute will dissolve in a specific

amount of solvent at a specific temperature to make a saturated solution.

• “Likes dissolve likes”- polar solvents dissolve polar solutes & nonpolar solvents dissolve nonpolar solutes.

• Hydrationis the solution process with water as the solvent.

• Hydrates are ionic compounds that have formed crystals that have incorporated water molecules in their structure.

• Immiscible liquids are not soluble in one another. eg. oil & water

• Miscible liquids dissolve freely in one another in any proportion. eg. water & alcohol

Page 9: [PPT]Modern Chemistry Chapter 12- Solutions - Licking … Chemistry Chapter 12... · Web viewModern Chemistry Chapter 12-Solutions Section 1- Types of Mixtures Solutions are homogeneous

Solubility• Increasing the pressure has no effect on the solubility of a solid in a liquid

but does increase the solubility of gases in a liquid.

• Increasing temperature often increases the solubility of a solid in a liquid but decreases the solubility of a gas in a liquid.

• Henry’s Law states that the solubility of a gas in a liquid is directly proportional to the partial pressure of the gas on the surface of the liquid.

• Effervescence is the rapid escape of a gas from a liquid in which the gas is dissolved.

• A solvated solute particle is surrounded by solvent molecules.

• Enthalpy of solution is the amount of heat absorbed by a solution when a specific amount of solute dissolves in a solvent.

Page 10: [PPT]Modern Chemistry Chapter 12- Solutions - Licking … Chemistry Chapter 12... · Web viewModern Chemistry Chapter 12-Solutions Section 1- Types of Mixtures Solutions are homogeneous

Problems• Do section review

questions #1, #2, #3, #5, & #6 on page 416.

• Read the Cross-Disciplinary Connection on page 417 and answer the questions at the end of the reading.

Page 11: [PPT]Modern Chemistry Chapter 12- Solutions - Licking … Chemistry Chapter 12... · Web viewModern Chemistry Chapter 12-Solutions Section 1- Types of Mixtures Solutions are homogeneous

Section 3Concentrations of Solutions

• The concentration of a solution is a measure of the amount of solute dissolved in a given amount of solvent or solution.

• Molarity (M) is the number of moles of solute in one liter of solution.

M = #mol L

• Do practice problems #1, #2, & #3 on page 421.

Page 12: [PPT]Modern Chemistry Chapter 12- Solutions - Licking … Chemistry Chapter 12... · Web viewModern Chemistry Chapter 12-Solutions Section 1- Types of Mixtures Solutions are homogeneous

Solution Concentrations

• Molality (m) is the concentration of a solution expressed in moles of solute per kilogram of solvent.

m = #mol kg

Do practice problems #1 & #2 on page 424.

Page 13: [PPT]Modern Chemistry Chapter 12- Solutions - Licking … Chemistry Chapter 12... · Web viewModern Chemistry Chapter 12-Solutions Section 1- Types of Mixtures Solutions are homogeneous

Solution Concentrations

• Percent composition by mass (%) is a concentration that expresses the percent of solute in a solution.

% = #g solute x 100 # g solution

Do section review problems #1, #2, & #3 on page 424.

Page 14: [PPT]Modern Chemistry Chapter 12- Solutions - Licking … Chemistry Chapter 12... · Web viewModern Chemistry Chapter 12-Solutions Section 1- Types of Mixtures Solutions are homogeneous

Chapter 12 Test Review• multiple choice (30)

– define & identify suspensions & solutions– define an alloy– define & identify electrolytes & nonelectrolytes– factors that affect the rate of dissolution– definitions of unsaturated, saturated & supersaturated solutions– general rules for predicting whether a solute is soluble in a

solvent– definition of solubility– effects of temperature & pressure on the solubility of gases and

solids in liquids– definitions of molarity (M) and molality (m)– solving molarity & molality problems– FORMULAS: M = #mol/L m = #mol/kg