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Investigation 2: ElementsMystery-Mixture Elements ...........................................................................................................................13Elements Questions ........................................................................................................................................15Elements in Products .....................................................................................................................................16Periodic Table ..................................................................................................................................................17Response Sheet—Elements ...........................................................................................................................19Elements in the Universe Questions ............................................................................................................21
Investigation 3: ParticlesHow Much Gas? A .........................................................................................................................................22How Much Gas? B ..........................................................................................................................................23What’s in the Bubbles? ...................................................................................................................................24Discuss Air as Particles ..................................................................................................................................25Air in a Syringe A ...........................................................................................................................................26Air in a Syringe B ............................................................................................................................................27Particles Questions .........................................................................................................................................29Three Phases of Matter Questions ...............................................................................................................31
Investigation 4: Kinetic EnergyHeating and Cooling Air A ...........................................................................................................................32Heating and Cooling Air B ............................................................................................................................33Heating and Cooling Water A ......................................................................................................................34Heating and Cooling Water B .......................................................................................................................35Particles in Motion Questions .......................................................................................................................37Response Sheet—Kinetic Energy .................................................................................................................39Expansion and Contraction Questions .......................................................................................................41
Investigation 5: Energy TransferMixing Water ...................................................................................................................................................43Energy on the Move Questions ....................................................................................................................45Response Sheet—Energy Transfer ................................................................................................................47Calculating Heat in Calories A .....................................................................................................................48Calculating Heat in Calories B ......................................................................................................................49Heat Transfer ...................................................................................................................................................51Heat Practice A ...............................................................................................................................................52Heat Practice B ................................................................................................................................................53
Investigation 6: Heat of FusionIce Water and Hot Water A ............................................................................................................................54Ice Water and Hot Water B ............................................................................................................................55Heat of Fusion A/Heat of Fusion B .............................................................................................................56Heat of Fusion C/Heat of Fusion D .............................................................................................................57Heat of Fusion Questions ..............................................................................................................................59
Investigation 7: Phase ChangeDissolve or Melt? A ........................................................................................................................................60Dissolve or Melt? B .........................................................................................................................................61Melt Three Materials ......................................................................................................................................63Wax and Sugar Questions .............................................................................................................................64Rock Solid Questions .....................................................................................................................................65Response Sheet—Phase Change ...................................................................................................................67Freeze Water A ................................................................................................................................................69Freeze Water B .................................................................................................................................................70Freeze Water C ................................................................................................................................................71Water-and-Ice System Observations ............................................................................................................73
Investigation 8: SolutionsMixtures A .......................................................................................................................................................74Mixtures B ........................................................................................................................................................75How Things Dissolve Questions ..................................................................................................................77How Much Will Dissolve? A .........................................................................................................................78How Much Will Dissolve? B .........................................................................................................................79Response Sheet—Solutions ...........................................................................................................................81Magnesium Sulfate Solutions .......................................................................................................................83Concentration Questions ...............................................................................................................................85
Investigation 9: ReactionRepresenting Substances ...............................................................................................................................86Analyzing Substances ....................................................................................................................................87Limewater Investigation A ............................................................................................................................88Limewater Investigation B ............................................................................................................................89How Do Atoms Rearrange? Questions .......................................................................................................91Acid/Soda Reaction Products ......................................................................................................................93Response Sheet—Reaction ............................................................................................................................95Lavoisier Questions ........................................................................................................................................97Heartburn Chemistry .....................................................................................................................................99
Investigation 10: More ReactionsCitric Acid/Baking Soda Reaction .............................................................................................................101Rust .................................................................................................................................................................103
Bess fi lled a syringe with water and left it by the sink in the sunshine. Ten minutes later she saw a little puddle of water under the syringe tip. Bess said,
This syringe must be broken. It’s leaking.
But it wasn’t broken.
What do you think caused the little puddle of water to appear under the syringe tip?
NOTE: Use the words particle and kinetic energy in your explanation.
2. Why do you think an ice cube feels cold when you hold it in your hand?
3. What will happen to a balloon stretched over the mouth of an “empty” bottle when the bottle is placed in hot water? Explain all the energy transfers.
4. When does energy flow from a cold object to a hot object?
5. What does a thermometer measure, and how does it do it?
When you put a bottle of juice in a cooler full of ice, the juice gets cold. That’s because the cold transfers to the juice and slows down the kinetic energy of the juice particles.
Comment on Julie’s ideas and give your explanation for why the juice gets cold.
Temperature is measured in degrees Celsius (°C). Heat is not measured in degrees Celsius. Heat is measured in calories (cal). The calorie is the unit of heat in the metric system.
One calorie is the amount of heat needed to raise the temperature of 1 g of water 1°C. For instance, it takes 1 cal of heat to raise the temperature of 1 g of water from 25°C to 26°C.
1. Calculate the number of calories needed to
CALCULATING HEAT IN CALORIES A
2. Billy mixed 40 g of 60°C water with 60 g of 25°C water. The final temperature was 39°C.
a. Calculate the change of temperature (∆T) for the hot water.
∆T = Tf – Ti
b. Calculate the amount of heat (calories) transferred from the hot water.
calories = mass of hot water ✕ change of temperature of hot water
cal = m ✕ ∆T
c. Calculate the amount of heat transferred to the cold water.
cal = m ✕ ∆T
d. Compare the amount of heat transferred from the hot water and the amount of heat transferred to the cold water.
3. Rosella has a 10-liter fish tank. The water needs to be 28°C for her tropical fish. When she filled the tank, the temperature of the water was 12°C. How many calories of heat must transfer to the aquarium before it is ready for the fish?
4. Cindy made tea. She started with 300 g of water at 20°C. She transferred 18,000 cal to the water. What was the final temperature of the water?
5. Lee’s 600-mL cup of cocoa got cold. It was only 25°C. He put it in the microwave. How many calories must transfer to the cocoa to bring it up to 70°C?
Some scientists landed on a planet that has an ocean of liquid tarpoo with solid chunks of tarpoo fl oating in it. The tarpoo was found to melt at 20°C. The scientists mixed solid and liquid tarpoo and took the temperature when the solid had all melted. Use their data to determine the heat of fusion of tarpoo.
HEAT OF FUSION A
Name
Period Date
HEAT OF FUSION B
Some scientists landed on a planet that has lakes of liquid grisk with pieces of solid grisk around the edge. The grisk was found to melt at 25°C. The scientists mixed solid and liquid grisk and took the temperature when the solid had all melted. Use their data to determine the heat of fusion of grisk.
Solid tarpoo 100 20°C 40°C 20 2,000
Liquid tarpoo 100 100°C 40°C 60 6,000
Starting temp. (T )
Ending temp. (T )
Change of temp. (ΔT )Material Mass (g)
Energy transfer (cal)
NOTE: 1 calorie (cal) = the amount of heat needed to change the temperature of 1 g of liquid tarpoo 1°C.
NOTE: 1 calorie (cal) = the amount of heat needed to change the temperature of 1 g of liquid grisk 1°C.
Some scientists landed on a planet that has large lakes of liquid neotrene with chunks of solid neotrene around the edges. The neotrene was found to melt at 15°C. The scientists mixed solid and liquid neotrene and took the temperature when the solid had all melted. Use their data to determine the heat of fusion of neotrene.
Some scientists landed on a planet that has pools of liquid simgob with crystals of solid simgob around the edge. The simgob was found to melt at 15°C. The scientists mixed solid and liquid simgob and took the temperature when the solid had all melted. Use their data to determine the heat of fusion of simgob.
Name
Period Date
HEAT OF FUSION C
HEAT OF FUSION D
NOTE: 1 calorie (cal) = the amount of heat needed to change the temperature of 1 g of liquid simgob 1°C.
NOTE: 1 calorie (cal) = the amount of heat needed to change the temperature of 1 g of liquid neotrene 1°C.
Randy watched his mom put a piece of wax in a pan. She put the pan on the stove. A minute later, Randy looked in the pan and said,
Look, the wax is turning into water.
What would you tell Randy to help him understand what happened in the pan?
Investigation 7: Phase ChangeNotebook Sheet
68
69
Name
Period Date
Materials
1 Glass thermometer
1 Metal-backed thermometer
1 Plastic cup
1 Vial
FREEZE WATER A
1 Stirring stick
• Sodium chloride, 3 spoons
• Ice, crushed
• Protective eyewear
Procedure
a. Fill a plastic cup halfway with crushed ice.
b. Put on protective eyewear. Add three 5-mL spoons of sodium chloride to the ice. Stir in thoroughly.
c. Put about 10 mL of water in a vial.
d. Carefully work the vial of water into the crushed ice. Make sure the surface of the water is below the level of the ice.
e. Monitor the temperature of the water in the vial with a glass thermometer.Monitor the temperature of the ice/salt environment with a metal-backed thermometer.
f. Record your observations. Include time, temperatures, and changes to the system.
a. Push the two clear plastic pipes through the holes in the rubber stopper.
b. Attach a long piece of tubing and a short piece of tubing to one pipe, as illustrated.
c. Put on protective eyewear. Measure 30 mL of limewater into the bottle. Insert the rubber stopper in the bottle.
d. Take turns using your straw mouthpieces to gently bubble one breath of air into the bottle through the long tube. Everyone should have at least two turns.
Results
Describe the changes you observed in the bottle.
Conclusion
Starting substances change into new substances during chemical reactions. Do you think a reaction occurred in the bottle? Why or why not?
1. Limewater is calcium hydroxide dissolved in water. The chemical formula for calcium hydroxide is Ca(OH)2. Use circles labeled with atomic symbols to draw what you think a representation of one particle of calcium hydroxide might look like.
2. a. Use atom tiles to make representations of the particles that you think reacted.
b. Rearrange the atoms to figure out what the white precipitate is.
c. Draw representations of the reactants and the products using labeled circles.
(HINT: The white powder does not dissolve in water.)
3. Write the limewater reaction using chemical formulas. Write the names of the reactants and products under the formulas.
4. Did new substances form? If yes, what are they?
1. What is destroyed and what is created during chemical reactions?
2. What are reactants and products? Write a reaction equation and label the reactants and products.
3. Write the equation for the reaction between hydrogen and oxygen. Use chemical formulas for the substances.
4. Methane (CH4) is the main gas in natural gas. The products that form when methane burns are carbon dioxide and water. Write a balanced equation showing the combustion reaction when methane and oxygen react.
1. Why did mercuric oxide in Lavoisier’s reaction chamber weigh more than the mercury metal?
2. Why was there less air in Lavoisier’s reaction chamber after he heated the mercury for 12 days?
3. What are some of the reasons Lavoisier is considered to be the father of modern chemistry?
Investigation 9: ReactionNotebook Sheet
98
99
Name
Period Date
HEARTBURN CHEMISTRYQuestion
How much stomach acid can one antacid tablet neutralize?
Materials
1 Plastic cup, 250-mL
1 Antacid tablet
1 Syringe, 35-mL, for measuring acid
• Hydrochloric acid (HCl)
• Protective eyewear
Procedure
Conclusions
1. How many milliliters of acid does one antacid tablet neutralize? __________________
2. The hydrochloric acid used in class is about 10 times more concentrated than real stomach acid. How many milliliters of real stomach acid will one antacid tablet neutralize? Show your math.
3. Write the chemical equation for the reaction between hydrochloric acid and the antacid.