SOLUTIONSChapter 15

Chemcatalyst:___.___• Think back to marking period one and define in your own

words the difference between a homogeneous and a heterogeneous mixture?

Mixtures

HOMOGENEOUS

• Uniform throughout• 1 continual phase

• Example: solutions like salt water

HETEROGENEOUS

• Not uniform throughout• Multiple phases

• Example: Oil and water

Other Heterogeneous Mixtures:

Suspension

• Particles are much larger• Do not stay suspend

indefinitely

• Particles begin to separate out

• Multiple phases

• Example: Clay in water or sand in water

Colloids

• Particles are medium-sized• Spread out and dispersed

• Cloudy or milky appearance

• Examples: Whipped cream, glue, milk, or mayo

Did you know?• Colloidal solutions, like fog, disperse or separate light!

• It is called the Tyndall effect!

• When light passes through it, the particles reflect or scatter the light in all different directions!

Mini Lab on types

PROPERTIES OF SOLUTIONSChapter 16

Chemcatalyst: __.__• Predict and explain whether sugar will dissolve faster in

iced tea or hot tea.

• Follow up: Which would dissolve faster cubed sugar or granular sugar?

Solutions, eh? • Solutions are homogeneous mixtures!

• Meaning same throughout

• They can be solids, liquids, or gases!

How do I make this said solution…?

SOLUTE

• The dissolved particles in a solution is known as a solvent

• The solute will become dispersed throughout the solvent

• Can be solids, liquids, or gases

SOLVENT

• The dissolving medium is the solvent

• The solvent dissolves the solute

• Can be solids, liquids, or gases

A solution has a solute and solvent

Why do you stir sugar into your tea?

Agitation• Stirring or shaking speeds up the solution process

• More of the solute will be brought into contact with solvent

• Only affects the time it takes to dissolve, not the amount of solute dissolving

• Insoluble will always be insoluble

Back to the C.C

Hot or cold tea dissolves sugar faster?

Temperature• High temperature, more kinetic energy molecules move

faster

• The rapid motion is an increase in collisions between the solvent and the solute

http://www.youtube.com/watch?v=cckAwavEKA0

Back to the C.C. follow upSugar cube or granular sugar dissolves faster?

Particle Size of Solute• The smaller the particles, the greater surface area to

collide with the solvent

• The more surface area, more collisions and the faster rate of dissolving

Chemcatalyst __.___• What does it mean if something is soluble?

• Give an example

Solubility• The amount of solute that dissolves in a given quantity of

solvent at a given temperature and pressure

• This amount creates a saturated solution

• Solubility is expressed in g/100 g H2O

Think about this…

Kool aid man, “Ohh yeaa” ©

• What if I put the entire container in?

• What does it look/taste like if I do not put all of it in?

Supersaturated vs Unsaturated

Supersaturated

• A solution that contains more solute that is able to dissolve

• Only so much will dissolve, the rest will be solid on the bottom

• Ex: Adding too much of the Kool Aid powder, rock candy

Unsaturated

• A solution that contains less solute than the saturated solution

• Ex: Not adding enough Kool Aid Powder

Did you know?• Miscible means soluble or the ability to dissolve in one

another• Example: Water and Ethanol

• Immiscible means they are insoluble• Example: Oil and water

Mini Lab • Solution and solubility mini lab

• Play at end of lab• http://www.youtube.com/watch?v=ghKUzh8l_t0

Factors affecting solubility

Temperature

• In general, the solubility of a solid increases as the solvent is heated

• In general, the solubility of a gas increases as the solvent is cooled

Pressure

• Little effect on the solubility of solids and liquids

• If the pressure above the liquid increases, the solubility of the gas increases

Henry’s Law• At a given temperature, the solubility of a gas in a liquid is

proportional to the pressure above the liquid.

• If the pressure increases, the solubility increases

• Example: Carbonated soda (CO2)

Chemcatalyst: __.___• What would you need to change?

• A saturated solution to an unsaturated solution• A saturated solution to a supersaturated solution• An unsaturated solution to a saturated solution

What is concentration?• The measure of the amount of solute that is dissolved in a

given solvent

• Depending on the amount it can be classified as dilute or concentrated

Concentration

Dilute solution

• A small amount of solute dissolved

Concentrated solution

• Large amounts of solute dissolved

*** Only qualitative, not QUANTITATIVE

If that’s qualitative, then how do we measure concentration?

Molarity (M)• Molarity is the number of moles dissolved in 1 liter of

solution

• Referred to a molar concentration or solution

• Units are moles/liter or represented as M (molar)

• Molarity = Moles of the solute

Liters of the solution** Volume must be in liters

Let’s calculate the molarity together!• What is the molarity of a solution that contains 0.70 mol of

NaCl in 250. mL?

• Molarity=

Try this one on your own:• IV fluid has 0.15 moles of saline solution in it, what would

the molarity be for 200. mL?

• Molarity=

How do you make a solution?

• Mini Lab• http://www.youtube.com/watch?v=cckAwavEKA0

Chemcatalyst: __.__• What would the molarity be a solution that has 0.0500

moles of solute and a given volume of 400. mL?

• Show work with units, try your best with SF

Dilution• To create a dilution, the number of moles of solution will

be reduced

• A dilution is created from a concentrated solution

• We use this equation:

M1V1 =M2V2

1 is initial conditions( concentrated solution)

2 is final conditions (dilute “new” conditions)

Let’s do this together!

• How many mL of 2.00 M MgSO4 solution must be diluted to prepare a 100.0 mL of 0.400 M MgSO4 ?

• M1= 2.00 M

• V1= ? mL

• M2= 0.400 M

• V2= 100.0 mL

M1V1 =M2V2

(2.00 M) V1= (0.400 M) (100.0 mL)

V1= 20.0 mL

Try this one on your own!• How many mL of a solution of 4.00 M KI are needed to

prepare 250.0 mL of 0.760 M KI

• M1= 4.00 M

• V1= ? mL

• M2= 0.760 M

• V2= 250.0 mL

M1V1 =M2V2

(4.00 M) V1= (0.760 M) (250.0 mL)

V1= 47.5 mL

Chemcatalyst: __.__• How many moles of ammonium nitrate are in 355 mL of a

0.425 M solution

0.151 mol

• How many mL of a 1.0 M solution to prepare 250. mL of a 0.20 M solution?

50. mL