• Classify the following as either a chemical change or a physical change:– Boiling – Burning

• On a molecular level, how would you describe the difference between boiling something, and burning something?

Bellwork: Monday 4/23/2012

Physical Change

Chemical Change

Different Phase- Still same bonds; farther apart, moving faster

NEW substance- Bonds broken, reformed

Think about it…

• A garden salad is made up of lettuce, tomatoes, cucumbers, ham, egg, bacon bits, and croutons.

• Compare this to dissolving sugar into un-sweet tea.– Hint: think about each

of them as different things being mixed together—what is the end result??

• The salad is not a uniform mixture (one bite is different from the next) – the salad is a heterogeneous mixture

• The tea is a uniform mixture – once dissolved, the sugar is spread out evenly in the tea so one sip tastes like another – the tea is a homogeneous mixture

Packet 12, Page 1- Mixtures & Solutions• Compound- two or more substances chemically

combined– Only separated by chemical means/reactions

• Examples of compounds:• Salt (NaCl) – Sodium & chlorine combined chemically• Water (H2O) – Hydrogen & oxygen combined chemically• Carbon Dioxide (CO2) – Carbon & oxygen combined chemically

• Mixture- two or more substances mixed together; NOT chemically combined– Separated by physical means

• Examples of mixtures:– Bowl of cereal – mixture of cereal and milk– Trail mix- mixture of various nuts, fruit, candy

• Air – mixture of gases• Soda pop – mixture of soda syrup, water, and CO2 gas• Fog – mixture of water and air• Table salt – compound of Sodium and Chlorine: NaCl• Kool-Aid – mixture of water, sugar, and flavor crystals• Water – compound of Hydrogen and Oxygen: H2O• Salt water – mixture of salt and water• Carbon monoxide – compound of Carbon and Oxygen: CO

Take a Guess! Mixture or Compound?

6.19- TSW USE EVIDENCE TO COMPARE AND CONTRAST HOMOGENEOUS AND

HETEROGENEOUS MIXTURES.• Heterogeneous mixture- a

mixture in which the properties are not uniform (ex. beef stew, garden salad) –“Uniform” means the same

throughout• Suspension- *solid is not

dissolved* Very fine particles of solid mixed with a liquid; often looks cloudy; eventually solid settles to the bottom

• Sediment- *solid is not dissolved and settles to the bottom*

• Homogeneous mixture- a mixture in which the properties are uniform (ex. sweetened tea)

• Solution- *solid is dissolved* mixture in which one substance is dissolved in another; has two parts:–Solute- is dissolved (s, l, g)–Solvent- does the

dissolving (s, l, g—usually liquid)• *The solute is present in a

smaller amount than the solvent*

• Solubility- How well a solute will dissolve in a solvent–Insoluble- does

not dissolve in water –Soluble- does

dissolve in water

6.21- TSW IDENTIFY THE SOLUTE AND SOLVENT IN A SOLUTION.

Solution Solute Solvent

Lemonade

Soda pop

Ocean water

Sugar (s) and Lemon Juice (l); Lemonade

powder (s)

Salt (s) Water (l)

CO2 – (g) carbonation/bubbles

Water (l) & Syrup (l)

Water (l)

(s) Means it is a SOLID; (l) LIQUID; (g) GAS

MatterSolid, liquid, gas

Pure SubstanceConstant Composition; Can

write chemical formula, homogeneous

ElementOne type of

atom

CompoundTwo or more different

types of atoms chemically bonded

MixtureVariable

Composition

Homogeneoussolutions

HeterogeneousColloids and suspensions

Matter: Pure Substances vs. MixturesPacket 12, Page 2

In-Class Work: Page 2- Classify Substance vs. MixtureType of Matter Substance- Element or

Compound?Mixture- Heterogeneous

or Homogeneous?Chlorine Water Soil Sugar water Oxygen Carbon dioxide Rocky road ice creamPure airSilver Ethyl alcohol (C2H5OH) Aluminum Table salt (NaCl) Sugar Seawater Chocolate chip cookie dough Vanilla ice cream

ElementCompound

Heterogeneous

Homogeneous

ElementCompound

Heterogeneous

HomogeneousElement

CompoundElement

Compound

Compound

Heterogeneous Homogeneous

Homogeneous

Page 5- Separating Mixtures Using Physical Methods:

6.20- TSW SEPARATE MIXTURES USING THE FOLLOWING PHYSICAL MEANS: FILTERING, MAGNETISM, DISSOLVING, AND EVAPORATION.1. Filtration- separates a solid (or

suspension) from a liquid– Example: separate dirt from some

salty water– How it works: The liquid (and anything

dissolved in the liquid) passes through holes in the filter paper. The solid particles are too big and get stuck.

2. Magnetism- separates objects with magnetic properties, from non-magnetic objects – Example: separate iron from sand– How it works: The magnet sticks to

the iron, not the sand.

3. Dissolving- causes solid matter to pass into a liquid solution; “disappears” – Example: the dissolving of salt

in water– How it works: Soluble solids will

dissolve, while insoluble solids will not

4. Evaporation- separates a dissolved SOLUTE from a SOLUTION– Example: obtain some pure salt

from salty water– How it works: When salty water

is warmed the water evaporates leaving behind crystals of salt.

5. Paper Chromatography- separates the different colors in dyes– Example: separate the different colored dyes in

ink pens – How it works: Place a dot of the dye to separate,

on chromatography paper, and then dip it into a solvent. As the solvent soaks up through the paper it carries the dye with it. The more soluble dyes move further up than the less soluble ones, hence separating from each other.

In-Class Work: Page 4

• Circle/write correct answers• Whatever is not finished is homework!

Bellwork: Tuesday 4/24/2012• Choose one of the five separation techniques we

have studied so far and describe how they can be used to separate a mixture, and what they separate.

1. Evaporation – how / what2. Magnetism – how / what3. Filtration – how / what4. Dissolving – how / what5. Chromatography – how / what

Separating Mixtures Lab- Page 5• Objective: Students will design, conduct, and

justify an experimental design in which they combine sand, iron filings, gravel, and salt, and then use physical means to separate the mixture.

• Data Table• Procedures• Conclusion Questions

• We will be working on this lab for one day. Your mixture should be completely separated by the end of today.

Separating Mixtures Lab Procedures - Page 5• Part 1 Procedure: – Measure and record the “original mass” of the sand, iron

fillings, gravel, and salt in the data table on pg. 6.– Combine the sand, iron fillings, gravel, and salt in a beaker;

stir until the substances are a complete jumble!• Challenge:– Along with your partners, you must now find a way to

separate the jumble that you have created in your beaker back into the original substances: sand, iron fillings, gravel, and salt.

– You may only use the tools you have been given!– Use Part 2 Procedure on pg. 6 to complete the challenge!– We don’t have a hot plate or blow dryer so MEASURE THE

MASS OF WATER IF YOU USE IT!!

Separating Mixtures Review• Filtration- separate a solid or suspension from a liquid– separating SAND from water

• Magnetism- separate magnetic objects from non-magnetic objects– separating iron from salt

• Dissolving- causes solid matter to pass into a liquid solution; “disappears”

• Evaporation- used to obtain the solute from a solution– obtaining SALT from salty water

• Chromatography- used to separate out one color from a mixture of colors– separating out the colors in black ink

Bellwork: Thursday 4/26/12

1. In the lab we did yesterday, what separation techniques worked for you and which ones did not?

2. Write the order of separation that you found to be the best.

Answer the following questions on your bellwork.

1. Filter the large gravel

from the sand, salt, iron

mixture.

2. Add water to the salt and sand mixture.

3. Shake well until the salt

dissolves. The sand does not

dissolve.4. Filtration: Use the filter paper and the funnel to filter into the beaker. The salt

solution passes through the paper. The sand remains

behind on the paper.

5. Evaporation: Put the salt solution in the evaporating basin and heat with the Bunsen burner. The water is evaporated. White

salt crystals will be left behind.

6. You can dry the sand by carefully heating the wet

filter paper.

7. You should now be left

with separate piles of salt and sand!!