Test 2 Review

Test Format

• Part I:– Lab set up– Follow directions, answer question, apply

information• Part II:– Written/computer test– 31 questions– Multiple choice– See score right away

Vocabulary• Chemical equation• Reactant• Product• Conservation of mass• Closed system • Open system• Photosynthesis• Respiration• Fire • Rust• Catalyst• Endothermic

• Exothermic• Precipitate• Chemical change• Physical change• Chemical property• Physical property• Evaporation• Freezing• Boiling• Flammability• Dependent variable• Independent variable

Chemical Equations

Can you identify:• Reactant + reactant product + product• product + product reactant + reactant

Practice

6 CO2 + 6 H20 C6H12O6 + 6 O2

carbon dioxide + water sugar + oxygenCircle the reactants:Box the products:

What is this equation?

Practice

Fe + O2 + H2O Rust

2Mg + O2 2MgO

Law of Conservation of Mass

• Total mass of reactants = Total mass of products

5g H20 + 5g O2 = _____ g 2H2O2

10g = 10g

Law of Conservation of Mass

• Same # of atoms on reactant side as the product side

2H2 + O2 2(H2O)

H= ____ H=____O= ____ O=____

42 2

4

Practice

Mg + O2 MgO

Mg = ____ Mg= ____O = _____ O = _____

Oxygen

MgMg

Oxygen

Oxygen

Is this balanced?

2 Mg + O2 ___ MgO

Mg = ____ Mg= ____O = _____ O = _____

NO

22

22

2

+

Produced a gas

(closed system)

(open system)

5g 85g ___ g

90 g

<90 g

Photosynthesis

6 CO2 + 6 H20 C6H12O6 + 6 O2

carbon dioxide + water sugar + oxygen

RespirationC6H12O6 + 6 O2 6 CO2 + 6 H20 + ATP

sugar + oxygen carbon + water + energydioxide

What influences the rate of a reaction (how fast it happens?)

• Crushing (size)• Stirring (motion)• Temperature• Amount of solution• Catalyst (substance that speeds up reaction)

Describing reactions

• Exothermic = ____________

• Endothermic = _________________

Heat given off

Heat taken in

How has understanding chemistry helped us?

• Inventions of new things• Discovery of new elements• Cooking• Forming new items

Property or Change?

• Property = describes, characteristicWhat it has the ABILITY to do

Change = actually changing

Property or Change?

• Boiling point of a chemical• 2 different liquids mix bubbles• Food coloring in water• Burning an egg• It has a yellow color• It produced a smell• It melted

Property

Property

Change

Change

Change

Change

Change

Physical or Chemical

• Physical = it looks different BUT the atoms are still the same

you could reverse it

• Chemical = may or may not look different BUT the atoms are rearranged differently

you CAN’T reverse it

PC or CC

• Tearing paper• Burning paper• Breaking wood• Campfire• Mixing kool aid• Cooking a cake• Freezing water

Physical change

Physical change

Physical change

Chemical change

Chemical change

Chemical change

Physical change

PPVolumeDensity

Freezes at 30 CBoiling point

Can melt at room temperatureFlexible

MagneticBouncyFloats

Solid, liquid, gas state of matter

CPFlammable/non flammable

Can rustCan tarnish

Can burnCan react with water

PCBreaking a stick

Dissolving kool aidFood coloring in a liquid

Cutting hairBending metal

Scrapping a crayonMelting chocolateEvaporated water

CCGas producedLight given off

Odor producedDiet Coke + Mentos = BubblesBaking Soda + Vinegar = colder

PhotosynthesisRespiration

RustingLeaves changing color

Remember

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