Chapter Menu Mixtures and Solutions Section 14.1Section 14.1Types of Mixtures Section 14.2Section 14.2 Solution Concentration Section 14.3Section 14.3 Factors Affecting Solvation Section 14.4Section 14.4 Colligative Properties of Solutions Exit Click a hyperlink or folder tab to view the corresponding slides.

Section 14-1 Section 14.1 Types of Mixtures Compare the properties of suspensions, colloids, and solutions. solute: a substance dissolved in a solution suspension colloid Brownian motion Tyndall effect soluble miscible insoluble immiscible Identify types of colloids and types of solutions. Describe the electrostatic forces in colloids. Mixtures can be either heterogeneous or homogeneous.

Section 14-1 Heterogeneous Mixtures A heterogeneous mixture is a mixture that does not have a uniform composition and in which the individual substances remain distinct. Suspensions are mixtures containing particles that settle out if left undisturbed.Suspensions

Section 14-1 Heterogeneous Mixtures Mississippi River Delta Snow Globes  150 million tons of sediment per year Suspensions settle out if left undisturbed, think:

Section 14-1 Heterogeneous Mixtures (cont.) Colloids are heterogeneous mixtures of intermediate sized particles (between 1 nm and 1000 nm) and do not settle out.Colloids Colloids are categorized according to the phases of their particles.

Section 14-1 Heterogeneous Mixtures (cont.)

Section 14-1 Heterogeneous Mixtures (cont.) Brownian motion is the jerky, random movements of particles in a liquid colloid, from the results of particle collisions.Brownian motion The Tyndall effect is when colloid particles scatter light as it passes through the mixture.Tyndall effect

Section 14-1 Homogeneous Mixtures Solutions are homogeneous mixtures that contain two or more substances. The largest component is called the solvent and all of the minor components are called solutes. Most solutions are liquids, but gaseous and solid solutions exist.

Section 14-1 Homogeneous Mixtures (cont.)

Section 14-1 Homogeneous Mixtures (cont.) If a substance dissolves in a solvent, we say it is soluble in that solvent.soluble Two liquids that are soluble in each other in any proportion are miscible.miscible A substance that does not dissolve in a solvent is insoluble. Two liquids that can be mixed but separate shortly after are immiscible.

A.A B.B C.C D.D Section 14-1 Section 14.1 Assessment Miscible substances are: A.two liquids that are not soluble in each other B.solids that dissolve in liquids C.solids that do not dissolve in liquids D.two liquids that are soluble in each other

A.A B.B C.C D.D Section 14-1 Section 14.1 Assessment The jerky, random movement of particles in a liquid colloid is known as ____. A.Brownian motion B.Tyndall effect C.Charles’s Law D.kinetic energy

End of Section 14-1

Section 14-2 Section 14.2 Solution Concentration Describe concentration using different units. solvent: the substance that dissolves a solute to form a solution concentration molarity molality mole fraction Determine the concentrations of solutions. Calculate the molarity of a solution. Concentration can be expressed in terms of percent or in terms of moles.

Section 14-2 Expressing Concentration The concentration of a solution is a measure of how much solute is dissolved in a specific amount of solvent or solution.concentration Concentration can be described as: concentrated = lots of solute dilute = small amount of solute

Section 14-2 Expressing Concentration (cont.)

Section 14-2 Expressing Concentration (cont.)

1. What is the percent by mass of salt in a solution made from 25.0 g of salt and g of water? 25.0 g salt X 100 =16.7% salt

2. You need to make mL of aqueous solution that is 5.0 % ethanol by volume. How would you make it? a) Determine the volume of ethanol b) Measure 12.5 mL and place it into a mL volumetric flask, then add water to a total volume of mL. (250.0 mL)(0.050) = 12.5 mL

Section 14-2 Expressing Concentration (cont.) Molality is the ratio of moles of solute dissolved in 1 kg of solvent.Molality moles = grams of solute molar mass kg = grams of solvent 1000 Molality (m) = moles of solute kg of solvent

3. What is the molality of NaCl in a solution that contains 11.7 g of NaCl in g of water? 11.7 g NaCl 58.5 g/mol =0.200 mol NaCl g water 1000 = kg mol kg = m NaCl

Section 14-2 Expressing Concentration (cont.) Mole fraction is the ratio of the number of moles of solute in solution to the total number of moles of solute and solvent.Mole fraction where X A and X B represent mole fractions of each substance

4. What is the mole fraction of methanol in a solution made from 50.0 g of methanol (CH 3 OH) and 50.0 g of ethanol (C 2 H 5 OH)? 50.0 g CH 3 OH 32.0 g/mol =1.56 mol CH 3 OH 50.0 g C 2 H 5 OH 46.0 g/mol =1.09 mol C 2 H 5 OH 1.56 mol CH 3 OH = CH 3 OH

Section 14-2 Expressing Concentration (cont.) Molarity is the number of moles of solute dissolved per liter of solution.Molarity Dilution equation: M 1 V 1 = M 2 V 2

5. What is the molarity of NaCl in a solution that contains 4.00 g of NaCl in mL of water? 4.00 g NaCl 58.5 g/mol = mol NaCl mL water 1000 = L mol L = M NaCl

6. What mass of NaCl is present in 3.00 L of M NaCl solution? Molarity (M) = moles L M x L = moles M x 3.00 L = mol NaCl mol NaCl x 58.5 g/mol = 35.1 g NaCl

7. If you add water to 25.0 mL of 2.00 M HCl until the solution has a volume of mL, what is the concentration of the diluted acid? (2.00 M)(25.0 mL) =(x)(500.0 mL) x = M HCl M 1 V 1 = M 2 V 2

A.A B.B C.C D.D Section 14-2 Section 14.2 Assessment Which is NOT a quantitative measure of concentration? A.molarity B.molality C.percent by mass D.dilute

A.A B.B C.C D.D Section 14-2 Section 14.2 Assessment The number of moles of solute divided by liters of solution is called ____. A.molarity B.molality C.percent by volume D.percent by mass