Solutions

SolutionsSolutionsChapter 8Chapter 8

ObjectivesObjectives• Review key principles from previous Review key principles from previous

chapterschapters• Recognize how a solution differs from Recognize how a solution differs from

other types of mixturesother types of mixtures• Name the different parts of a solution.Name the different parts of a solution.• Distinguish how properties of solutions Distinguish how properties of solutions

differ from properties of their original differ from properties of their original components.components.

• Observe in an experiment how to Observe in an experiment how to separate the components of a solution.separate the components of a solution.

Things to Remember…Things to Remember…

• A change in state is a ______________ change. EX)

• Chemical reactions _____________ bonds between atoms

• Law of Conservation of mass states that the number of ___________ in the products must equal the number of atoms in the _________________.

PHYSICAL

REARRANGE

ATOMS

REACTANTS

Things to Remember…Things to Remember…•A ______________________ can be created

through covalent or ionic bonds. A ________________ can only be created through a covalent bond (EX. Water Molecule).

•The temperature at which a liquid becomes a solid is called its _____________________. The temperature at which a liquid rapidly becomes a gas is called its ________________________.

COMPOUND

MOLECULE

FREEZING POINT

BOILING POINT

A Solution is a Type of A Solution is a Type of MIXTUREMIXTURE1. A solution is actually a ___________________ mixture because it is the same throughout, but a solution CAN be _________________ by physical means. The substances in a mixture DO NOT ____________ ____________.

2. All proportions of a solution have the _________ _____________.

HOMOGENOUS

SEPARATED

REACT CHEMICALLY

SAME PROPERTIES

Solution or NotSolution or Not

Kool-Aid is a SOLUTION!!!!!

Water (by itself) is not a solution, but we can use water to make different

solutions.

SoluteSoluteA. The ____________________ is a substance that is dissolved to make a solution. When it dissolves it separates into _______________ ______________.

SOLUTE

INDIVIDUAL PARTICLES

SolventsSolventsB. The __________________ is a substance that dissolves a solute. ______________ is the most commonly used solvent (We even call it the “Universal Solvent”)

DID YOU KNOW????DID YOU KNOW????

• It is not possible to identify the It is not possible to identify the solute and solvent as different solute and solvent as different substances when they form a substances when they form a solution!!!solution!!!

SOLVENT

WATER

SOLUTESSOLUTES DISSOLVE IN DISSOLVE IN

SOLVENTSSOLVENTS

Types of SolutionsTypes of Solutions

4. Solutions can be 4. Solutions can be SOILDSOILD, , LIQIUDLIQIUD, or , or GASGAS. .

•For example, Oxygen is a gas dissolved For example, Oxygen is a gas dissolved in sea water.in sea water.

•Page 240Page 240

Types of SolutionsTypes of Solutions

• Some solutions are in the Some solutions are in the same physical state.same physical state.

• For example: Vinegar is a For example: Vinegar is a solution of acetic acid and solution of acetic acid and water.water.

A. If solutions are in the same state of matter (EX. 2 Liquids), the substance present in the greatest amount is considered to be the ______________________.

SOLVENT

Types of SolutionsTypes of Solutions

• Do solutions ever exists as a solid???Do solutions ever exists as a solid???

• Yes, Yes, BronzeBronze is a solid solution in which is a solid solution in which tin is the solute and copper the tin is the solute and copper the solvent.solvent.

• Do solutions exists as gases???Do solutions exists as gases???

• Of course, think about Of course, think about the air we the air we breathebreathe!!

SuspensionsSuspensions

• In a suspension , In a suspension , the particles are the particles are larger than those larger than those found in a solution.found in a solution.

• Instead of Instead of dissolving they are dissolving they are suspended.suspended.

Solvent & Solute Particles Solvent & Solute Particles InteractInteract

• The parts of a solution—that is, the The parts of a solution—that is, the solute and the solvent—can be solute and the solvent—can be physically separated because they physically separated because they are not changed into new are not changed into new substances.substances.

• However, individual particles of However, individual particles of solute and solvent do interact.solute and solvent do interact.

• The solute particles become evenly The solute particles become evenly distributed throughout the solvent.distributed throughout the solvent.

Interaction continued…Interaction continued…• The way compounds dissolve The way compounds dissolve

depends on the type of bonds in the depends on the type of bonds in the compound.compound.

• Ionic compounds Ionic compounds like table salt, like table salt, split into individual ions.split into individual ions.

• Covalent compounds Covalent compounds like table like table sugar, dissolve and each molecule sugar, dissolve and each molecule stays together and is surrounded by stays together and is surrounded by solvent molecules.solvent molecules.

Properties of SolventsProperties of Solvents

• In every solution, solutes change the physical properties of a solvent: – They always ___________________ the

freezing point (Adding salt to roads during snow storms)

– They always___________________ the boiling point (Adding antifreeze to your car)

LOWER

RAISE

Lowering the Freezing PointLowering the Freezing Point

• Page 243Page 243

Raising the Boiling PointRaising the Boiling Point• Putting salt in water can Putting salt in water can

raise the boiling point.raise the boiling point.• The amount of salt in the The amount of salt in the

water determines how water determines how much the boiling point is much the boiling point is increased.increased.

• Example for both lowering Example for both lowering and raising temperature: and raising temperature: Antifreeze!Antifreeze!

• How do you think it works?How do you think it works?

SuspensionsSuspensions

7. 7. In a ___________________, the particles are larger than those found in a solution. EX)Suspensions are not ______________.

SUSPENSION

FLOUR IN WATERSOLUTIONS

8.2 Objectives8.2 Objectives• Explain how the concentration of a Explain how the concentration of a

solution varies.solution varies.

• Describe how a solute’s solubility can Describe how a solute’s solubility can be changed.be changed.

• Recognize that solubility depends on Recognize that solubility depends on molecular structure.molecular structure.

ConcentrationConcentration

A solution’s CONCENTRATION depends on the amount of solute dissolved in a solvent at a particular temperature. EX) “Orange Juice Concentration” simply means how much juice is dissolved into water.

Concentration Can VaryConcentration Can Vary• A DILUTE solution has a low

concentration of solutes (It has a higher level of solvents)

• A SATURATED solution has a high concentration of solutes (It has a lower level of solvents)

• You can raise the concentration by adding more SOLUTES or decrease the concentration by adding more SOLVENTS.

• A SUPER SATURATED solution contains more solutes than is normally possible.

SOLUBILITYSOLUBILITY

9. The SOLUBILITY of a substance is the amount of the substance that will dissolve in a certain amount of a solvent at a given temperature

– If the solute is highly soluble, a saturated solution will be very CONCENTRATED.

– If a solute has a low solubility, the saturated solution will be DILUTE.

Changing SolubilityChanging Solubility• We can change the solubility

of a solute. There are two different ways:– To dissolve more solid into a

liquid, we simply raise the TEMPERATURE. The solid will dissolve quicker and more of it will dissolve in a given solvent.

– To dissolve more gases into a liquid, we must increase the PRESSURE. Increasing the temperature of a gas will actually make it less soluble.

TemperatureTemperature

• Increase in Increase in Temperature:Temperature:– Solutes dissolves Solutes dissolves

more quicklymore quickly– Greater amount Greater amount

of solid dissolves of solid dissolves in a given amount in a given amount of solvent.of solvent.

– Page 249Page 249

Temperature & GasesTemperature & Gases

The opposite is true for gases—an The opposite is true for gases—an increase in temperature makes a gas increase in temperature makes a gas less soluble in water.less soluble in water.

Pressure & SolubilityPressure & Solubility

• Cokes add COCokes add CO2 2 gas gas at a pressure at a pressure slightly greater than slightly greater than normal air pressure. normal air pressure.

• When you open the When you open the can, the pressure can, the pressure decreases and the decreases and the Carbon dioxide Carbon dioxide bubbles out of bubbles out of solution with a fizz!solution with a fizz!

• Scuba tanks include Scuba tanks include 79% N. People 79% N. People breathe like this all breathe like this all the time without the time without any problem, but any problem, but the pressure the pressure underwater is much underwater is much greater than on greater than on Earth’s surface.Earth’s surface.

• The higher pressure The higher pressure increases the increases the solubility of N in the solubility of N in the diver’s blood.diver’s blood.

DiversDivers

• When a diver heads up to the surface When a diver heads up to the surface too fast, the pressure decreases, and too fast, the pressure decreases, and so does the solubility of N.so does the solubility of N.

• The N comes out of solution and into The N comes out of solution and into the diver’s blood. These bubbles can the diver’s blood. These bubbles can cause painful and sometimes fatal cause painful and sometimes fatal condition called the “bends.”condition called the “bends.”

To Prevent The Bend’sTo Prevent The Bend’s

• Divers can rise to the surface slowly, Divers can rise to the surface slowly, so bubbles stay small.so bubbles stay small.

• They can breathe a different mixture They can breathe a different mixture of gases, which contains only 66% of of gases, which contains only 66% of N.N.

Temperature and SolubilityTemperature and Solubility

SoluteSolute Increased Increased TemperatuTemperaturere

Decreased Decreased TemperaturTemperaturee

SolidSolid Increase is Increase is SolubilitySolubility

Decrease in Decrease in SolubilitySolubility

GasGas Decrease in Decrease in SolubilitySolubility

Increase in Increase in SolubilitySolubility

This is how we make This is how we make SUPER SATURATED SUPER SATURATED

solutions! solutions!

Supersaturated SolutionsSupersaturated Solutions

ConcentrationConcentration• A solution’s concentration depends A solution’s concentration depends

on the amount of solute dissolved in on the amount of solute dissolved in a solvent at a particular temperature.a solvent at a particular temperature.

• Is it easier to make lemonade with or Is it easier to make lemonade with or hot or cold water?hot or cold water?

Solubility Depends on Solubility Depends on Molecular StructureMolecular Structure

• When a substance dissolves, the molecules separate from one another and become evenly mixed

• A POLAR substance attracts a POLAR substance to form solutions.

• “Like dissolves like”

• PAGE 251

What Would Happen????What Would Happen????

• What would happen if I mixed water, What would happen if I mixed water, oil and corn syrup in the same oil and corn syrup in the same bottle?bottle?

Do Oil and Water Mix?Do Oil and Water Mix?

ReviewReview

• Why will a nonpolar substance not Why will a nonpolar substance not dissolve in a polar substance?dissolve in a polar substance?– Nonpolar solutes do not have a charged Nonpolar solutes do not have a charged

regions that would be attracted to regions that would be attracted to charged regions of polar solvents.charged regions of polar solvents.

• How does pressure affect the How does pressure affect the solubility of solids? Of gases?solubility of solids? Of gases?– Solid and liquid solutes are not affected Solid and liquid solutes are not affected

by pressure. An increase in pressure by pressure. An increase in pressure increases solubility of gases.increases solubility of gases.

ReviewReview

• What effect does temperature have on What effect does temperature have on most solid solutes? On gases solutes?most solid solutes? On gases solutes?– Increase in temp increases the solubility of Increase in temp increases the solubility of

most solid solutes. Increase in temp decreases most solid solutes. Increase in temp decreases the solubility of gases.the solubility of gases.

What do these terms mean: dilute and What do these terms mean: dilute and saturated?saturated?

Dilute- low concentrationDilute- low concentration

Saturated- Contains maximum amount of soluteSaturated- Contains maximum amount of solute

Acids, bases and Acids, bases and saltssalts

Section 3Section 3

Chapter 8Chapter 8

Our learning goals for this Our learning goals for this section:section:•To learn about acids and To learn about acids and basesbases

•To learn how to determine if To learn how to determine if a solution is acidic or basica solution is acidic or basic

•To learn how acids and To learn how acids and bases react with each otherbases react with each other

Acids & Bases BasicsAcids & Bases Basics12. Acids and Bases are formed when solutions are dissolved in WATER. When they dissolve they produce an ION, or charged particle. ******EX) If a hydrogen atoms loses its electron, it becomes positive (it’s actually just a PROTON.)13. Acids and bases are classified based on their ability to either accept or donate these hydrogen ions (or PROTONS)

How do we measure acids & How do we measure acids & basesbases

• pH scale (pg 258)pH scale (pg 258)

Properties

Acids Bases

Does it donate or accept

hydrogen ions?

Donates hydrogen ions

Accepts hydrogen ions

pH  

0-6 

8-14Taste  

Sour BitterTouch  

Burning/Itching 

SlipperyExample  

HCl-Hydrochloric Acid

 NaOH-Sodium Hydroxide

It is all about the IONS…..It is all about the IONS…..

• Remember an ion is a charged Remember an ion is a charged particle. And if a hydrogen atom particle. And if a hydrogen atom loses an electron it becomes a loses an electron it becomes a hydrogen ion. Which is simply a hydrogen ion. Which is simply a proton and has a positive charge.proton and has a positive charge.

• An acid is defined as a substance An acid is defined as a substance that can donate a hydrogen ion (a that can donate a hydrogen ion (a proton) to another substance.proton) to another substance.HCl → H+ + Cl-

H2O

IONS CONT.IONS CONT.• A base is a substance that can accept a A base is a substance that can accept a

hydrogen ion from another substance.hydrogen ion from another substance.

• So just generally speaking the difference So just generally speaking the difference between an acid and a base is that acids between an acid and a base is that acids donate protons and bases accept protons. donate protons and bases accept protons.

• A~DA~D• B~A…………….B~A…………….babasesses

NaOH → Na+ + OH-H2

O

Characteristics of acidsCharacteristics of acids

•Tastes sourTastes sour

•Strong acids are corrosive Strong acids are corrosive and poisonand poison

•Hydronium ions in all acidsHydronium ions in all acids

•Variety of changes to Variety of changes to indicatorsindicators

Characteristics of basesCharacteristics of bases

•Tastes bitterTastes bitter

•Feels slipperyFeels slippery

•Strong bases can be Strong bases can be corrosive and poisoncorrosive and poison

•OHOH-- ion present in all bases ion present in all bases

Not all acids and bases are alike. They can vary in STRENGETH.

-When a STRONG ACID is dissolved in water, it separates almost completely into ions (H+). -When a WEAK ACID is dissolved in water, it does not form many ions. -When a STRONG BASE is dissolved in water, it separates almost completely into ions (OH-)-When a WEAK BASE is dissolved in water, it does not form many ions. **PAGE 256 for examples

Strong acid and weak acidStrong acid and weak acid

Strong base and weak base

NeutralizationNeutralization16. Acids & Bases will NEUTRALIZE each other. The neutral pH is 7. ***The H+ collides with the OH- to create H2O!!! *** Other atoms will create the salts!

The neutralization processThe neutralization process• When you have an upset tummy your When you have an upset tummy your

stomach is producing too much HCl. stomach is producing too much HCl. The pH is about 1.5. You take an The pH is about 1.5. You take an antacid that contains a base and the antacid that contains a base and the base reacts with the acid to produce a base reacts with the acid to produce a salt and water.salt and water.

• So an acid + base gives a salt + water.So an acid + base gives a salt + water.

• Two very harmful things come together Two very harmful things come together to produce two very harmless things.to produce two very harmless things.

• This is called the neutralization process.This is called the neutralization process.

Explore acids and basesExplore acids and bases• What are some observations we can What are some observations we can

make about this cup of vinegar?make about this cup of vinegar?

• What happens when we add 2 What happens when we add 2 crushed alka seltzer tablets?crushed alka seltzer tablets?At the start of the demo looked like water but had a strong smell. After the addition of the alka seltzers the mixture fizzed and bubbles were produced. The vinegar odor was not as strong. So when you have a tummy ache you take an antacid to neutralize the acid being produced by the lining in your stomach.

8.4 Objectives8.4 Objectives

You will learnYou will learn

-How metal alloys are made-How metal alloys are made

-How a variety of alloys are used in -How a variety of alloys are used in modern societymodern society

-Why different alloys have different -Why different alloys have different propertiesproperties

What is an alloy?What is an alloy?

• An alloy is a mixture of a metal An alloy is a mixture of a metal and one or more other elements, and one or more other elements, usually metals as well. usually metals as well.

Making AlloysMaking Alloys• First, we melt the First, we melt the

metalsmetals

• Then, mix them Then, mix them togethertogether

• Finally, we allow Finally, we allow them to cool to a them to cool to a solidsolid

• EX) SteelEX) Steel

Alloy PropertiesAlloy Properties

• Alloys have different Alloys have different properties than the elements properties than the elements that make them up.that make them up.

• The alloy BRONZE is harder The alloy BRONZE is harder than either copper or tin than either copper or tin alonealone

• Nitinol (nickel & titanium) has Nitinol (nickel & titanium) has the ability to form to a the ability to form to a particular shape, be moved particular shape, be moved to another shape, and then to another shape, and then reform to its original shapereform to its original shape

How Do We Use Alloys?How Do We Use Alloys?• Steel makes up many Steel makes up many

of our large buildingsof our large buildings

• Steel makes up many Steel makes up many of the ships we use of the ships we use (including cruise (including cruise liners)liners)

• Most vehicles are Most vehicles are built with many types built with many types of alloysof alloys

• Medical Equipment is Medical Equipment is made of stainless made of stainless steelsteel

Alloys are also used in Alloys are also used in Space FlightSpace Flight

• They allow airplanes to be They allow airplanes to be lightweight, yet stronglightweight, yet strong

• Research on the space Research on the space station has allowed scientist station has allowed scientist to make alloys in a to make alloys in a microgravity environmentmicrogravity environment

• The alloy research could The alloy research could lead to new innovations in lead to new innovations in robotics & creating artificial robotics & creating artificial organs for humansorgans for humans