Homework9-23-11

Vocabulary chapter 18, section 1 and 2 Page 528 and 540

10 words

Bell Work – write question, answer and explanation 9-24-11

A substance is mixed into a solution. If there is no chemical reaction, what will happen when the liquid is evaporated out of the mixture?

a. The container will be emptyb. The container will have residue of the solid

that was originally dissolvedc. The mixture cannot evaporated. None of the above

Homework9-24-11

Read ch. 18 section 1: Page 528 to 539

Answer questions 1-5 at the end of the section (p 539)

GET TEST PAPER SIGNED!!!

Bell Work – write question, answer and explanation 9-28-11

Carbonation is mixing a gas into a liquid such as when soda pop drinks are made. Which answer is correct? Explain your answer.

a. This is a chemical changeb. This is a physical changec. Gas cannot be mixed into a liquid d. The gas is the solvent and the liquid is the

solute of the solution

Homework9-28-11

Read chapter 18 section 2: Page 540 to 546

Answer questions 1-5 at the end of the section (p 546)

QUIZ TOMORROW

What is Matter?

Anything that has mass and takes up space.STUFF!

What instrument is used to measure mass?

• A balance

• Scales are used to measure weight.

What are some examples of matter?

• List some……

• What about air, is it matter? Does it have mass?

What are the three most common states of matter?

1. solid2. liquid3. Gas

Lets demonstrate!!!!!!!!!

See particle movement for each phase

Demonstration

• Lets create our own Human Molecules Demonstration!!!

2 other states of matter…..

• Plasma (super excited and super hot atoms) *examples: neon signs, ball lightening, stars

• Bose Einstein condensate (super unexcited and super cold atoms)

See States of Matter

The Water Cycle is an example of state changes in nature

• Water from Earth evaporates into water vapor– Because it heats up

• Water vapor condenses and forms clouds– Because it cools down• It can become ice, snow or hail if it cools enough

Water precipitates as and it all starts over again!

Can you name other state changes we observe?

Can you name other state changes we observe?

• Chocolate in a hot car melts– Solid to liquid

• Will it become a solid again?• Is it still chocolate?– Then it is still the same substance so it is a physical

change.

• What about cheese, plastic, popsicles…?

The state of matter a substance is at room temperature is a physical

property that can be used to identify the substance.

• What is water at room temperature?• What is plastic at room temperature?• What is helium at room temperature?

What causes the states of matter to change?

• ENERGY…• Heat added changes a solid to liquid to gas• Heat taken away changes gas to liquid to solid

What are the changes of matter called?

• Solid to liquid…..melting• Liquid to solid…..freezing• Liquid to gas…..evaporation• Gas to liquid….condensation• Solid to gas….sublimation

What determines how fast the state of matter changes?

• Pressure and heat• The starting temperature• The amount of the substance that undergoes

change• The amount of heat that is applied to the

substance• The surface area is another factor that

determines how fast a substance will melt or boil.

How do we describe matter?

• Physical properties• Chemical properties

Physical properties

• Properties that do not change the chemical nature of the substance

Link

Physical Property Description

Color, Shape, Length, Mass

Volume Amount of space an object takes up

Density D=m/v

solubility Ability to Dissolve

Boiling point At 1 atmosphere water boils at: 100 oC 212 Fahrenheit 373 K

Freezing point 0 oC or 32 Fahrenheit

Melting Point Point at which a solid becomes a liquid

magnetic

Physical Property Descriptionductility

malleability

Chromatography

Chromatography is a method for separating substances in some mixtures.•Different substances of the mixture have different solubility rates.

•If the substance is very soluble, it moves up the paper quickly.•If the substance is less soluble, it creeps along very slowly.

Physical Changes

• Observe some examples.

• What about solubility and phase changes?

Mixture

• A mixture is made of two or more substances that come together, but DO NOT CHEMICALLY combine.

• Homogenous mixtures: are evenly mixed– Like tea or Koolaide

• Heterogeneous mixtures: are unevenly mixed– Like a pizza or salad

Solution• A solution is a mixture in which the different

particles are tiny and are mixed completely evenly

• EXAMPLES:• Liquid dissolved in liquid (sugar in water)• Liquids dissolved in other liquids (water in

alcohol)• Gas dissolved in a gas (oxygen dissolved in the

nitrogen in the air)• Gas dissolved in a liquid (carbonated drink)

Soluble

• The ability to be dissolved.

What determines solubility?

• The temperature and the amount of the solvent

What is the difference between solute and solvent

• Solute: The dissolved substance in a solution.• ( sugar and tea dissolved in water)

• Solvent: The dissolving agent in the solution, usually a liquid such as water.

• ( Water is considered the universal solvent)

Precipitate

• As the solution cools, the solute will fall out of the mixture.

• How is this similar to weather precipitation?

Saturated

• This is when no more solvent can be dissolved in the solution

Chemical Properties

• Properties that do change the chemical nature of matter.

Chemical Property DescriptionAbility to burn

Ability to react with oxygen

pH

Acids and Bases: pH

• http://www.composiclean.com/sitebuildercontent/sitebuilderpictures/phscaleWeb.jpg

Chemical Changes

• Observe some examples of chemical changes

• Hints that indicate a chemical change has taken place: change in temperature, color change, giving off gas – bubbles

Physical Change Chemical Change

Compound

• Compounds can only be broken down by chemical means

• They have a fixed ratio or proportion of atoms• An example is water