p. 75 Internal Energy IPS Unit 3 Semester 1 Name Teacher Hour

Transcription

1 p. 75 Internal Energy IPS Unit 3 Semester 1 Name Teacher Hour

2 Model of Internal Energy p. 76 Lab or Class Activity Observations Piece of Model Hot, Warm Cold: What s the difference? Test tube Colored Water Activity Hanger Lab Transimeter Lab BB Lab How Does it Feel? Lab

3 p. 77 What is ENERGY? Energy is an essential component of how and why things work and exist in our universe. Energy can be found in various forms, divided into different types, and measured in different ways. Use your knowledge and understanding of energy to answer the following questions about ENERGY! Please write down your own definition of energy below: As you view the power point, answer the questions below under the column that says, my ideas. Once the power point is complete, share your ideas with a partner. Write down your partner s ideas under the column that says, my partner s ideas. Be ready to share these ideas in the class discussion that follows. My Ideas My Partner s Ideas Example #1: What is the purpose of this item? Can this item be considered energy? Why or why not? Example #2: What is the purpose of this item? Can this item be considered energy? Why or why not? Example #3: What is the purpose of this item? Can this item be considered energy? Why or why not? Example #4: What is the purpose of this item? Can this item be considered energy? Why or why not? Please write down your NEW definition of energy below:

4 Review of the Model of Matter p. 78 Big Ideas: Matter is made from that are always. Matter is found in 3 main forms,, and. Particles in a solid are and move. Particles in a liquid are and move. Particles in a gas are and move. Demonstration: Title: Popcorn as Particles Purpose: To understand how particles move in a solid, a liquid, and a gas. Hypothesis: What do you think will happen as we heat the butter and popcorn mixture? Introduction: The object of the game is to use popcorn kernels as molecules and the butter as the bonding forces between them. Heating produces physical changes in the popcorn-butter mixture, which are analogous to the melting and boiling of matter. Materials and Safety Considerations: Popcorn/Butter combination Hot plate Beaker Hot plate, beaker, and contents will be hot use caution. Popcorn may fly from beaker; beware. Procedure: 1. Observe the popcorn-butter mixture. Record your observations in the data table. 2. Place the popcorn-butter mixture in a beaker on the hot plate. 3. Observe the popcorn-butter mixture every minute and record your observations in the data table. 4. Complete the conclusion section of this demonstration. Data and Observations: Time Observations Time Observations 0 min 11 min 1 min 12 min 2 min 13 min 3 min 14 min 4 min 15 min 5 min 16 min 6 min 17 min 7 min 18 min 8 min 19 min 9 min 20 min 10 min 21 min Conclusion:

5 p. 79 The popcorn kernels represented and the butter represented. When the popcorn-butter mixture was a solid the popcorn kernels were and the butter was. When the popcorn-butter mixture was a liquid the popcorn kernels were and the butter was. When the popcorn-butter mixture was a gas the popcorn kernels were and the butter was. As the temperature popcorn-butter mixture increased the popcorn kernels. If I were to heat up gold I would expect that the particles would as the temperature increased. STOP i) What is energy? Energy Notes ii) The two main types of energy (a) Potential energy (b) Kinetic Energy iii) Conservation of Energy

6 IPS Moving Particles p. 80 Purpose: To observe the movement of particles under different conditions Materials: Test tube, water, food coloring, stopper with thin glass tube, hot and cold water baths, test tube tongs. Procedure: 1) Fill tube to top with colored water and put the stopper in. 2) Mark a line where the water level is in the small tube. (Note: The level should be about half-way up the tube. If it is higher, adjust the stopper until the water lowers). 3) Place the tube in the COLD water bath first and record your observations. Mark where the water level is in the tube. 4) Then place the tube in HOT water and record your observations. 5) Repeat numbers 4 and 5 to find pattern. Data: What Happened? Cold Water Bath Hot Water Bath How long did it take? Pattern: Draw a picture of the particles when in cold water, hot water and room temperature water: HOT ROOM TEMPERATURE COLD

7 Temperature Notes p. 81 Instruments for measuring temperature (T) Temperature scales and units: Temperature is measured in degrees, but there are three different scales we can to measure temperature. F= K= C= Temperature Conversions: Converting from F to C (Estimation) Converting from C to F (Estimation) C to K K to C

8 Temperature Conversions Practice p. 82 Now that you have learned how to convert from Celsius to Fahrenheit and vice versa, let s do some practice problems. Be sure to show your work (including the equation you are using), use units, and circle your answer. From F to C 1. Write the equation we are using in class to convert from F to C. 2. The average temperature in Madison in November is 35.5 F. Convert that to C. 3. The highest temperature in the western hemisphere was 134 F measured at Death Valley, CA.. Convert that to C. 4. The boiling point of gold is 5,173 F. Convert that to C. 5. The average internal temperature of a dog is 101 F. Convert this to C. 6. The coldest temperature reached in the continental US was 70 F in Rodgers Pass, MT. Convert this to C. From C to F 7. Write the equation we are using in class to convert from C to F. 8. The average temperature in Bangkok Thailand in November is 26.8 C. Convert this to F. 9. The temperature of a lava flow is usually around 850 C. Convert this to F. 10. The highest temperature recorded on earth was 58.7 C in Al 'Aziziyah, Libya. Convert this to F. 11. The average internal temperature of an elephant is 36.4 C. Convert this to F. 12. The coldest Place on earth is Vostok, Antarctica. The coldest it ever got there was 89.2 C. Convert this to F.

9 IPS Hot, Warm, Cold: What s the difference? p. 83 Imagine you held your left hand in a bucket of ice water for about 1 minute, and at the same time you put your right hand into hot water for 1 minute. Immediately after that you put both of your hands into a bucket of room temperature water. Ice Water Hot Water What would the water feel like to each of your hands? Would that bucket of water be hot, cold, or something else? You have come up with a hypothesis, an idea of what temperature the bucket of water would have after placing your hands in buckets of cold and hot water. You can find out if your hypothesis or guess was correct by carrying out the following activity: Observations: 1. With permission, fill a container with cold water and put in some ice cubes. 2. Fill a container with water as hot as you can stand. 3. Fill a third container room temperature water neither hot nor cold. This container should be big enough for both of your hands. 4. Put one hand in the cold water and the other into the hot water for 1 minute. 5. After one minute, place both of your hands in the room temperature water. 6. Write your observations below. My hand that was in the cold water felt: My hand that was in the hot water felt:

10 IPS Hanger Lab p. 84 Purpose: To observe the changes when simple work is done to a hanger. Materials: One hanger and a balance. A C Procedure: 1. Working in pairs, get a hanger from your teacher. B 2. Mass your hanger and record its mass in the data table below. 3. Feel points A, B, and C and record your observations in the data table below. 4. Grab the hanger at points A and C and bend it rapidly 10 times. 5. Feel points A, B, and C and record your observations in the data table below. 6. Grab the hanger at points A and C and bend it rapidly 10 times, immediately mass your hanger and record the mass in the data table below. Data Table: Mass (in grams) Observations (at points A, B, and C) Before Bending A- B- C- After Bending A- B- C- Analysis: 1. Draw a picture showing the molecules in the hanger at point A, B, and C before bending. 2. Draw a picture showing the molecules in the hanger at point A, B, and C after bending. 3. Based on what you know about matter and energy, how can you explain your observations?

11 IPS Transimeter Lab p. 85 Purpose: To collect data to see how internal energy is transferred. Procedure: 1) Set up the thermal transimeter as shown by your teacher. Be sure to adjust the rubber rings on the thermometer so that the bulb of the thermometer is in the center of the chamber! 2) Make sure the thermal barrier block is in the middle groove with the SILVER SIDE FACING THE BULB. 3) Now put the cover on, plug it in and turn it on. 4) IMPORTANT: Watch the thermometer and TURN THE TRANSIMETER SWITCH OFF when the TEMPERATURE REACHES 70 C and REMOVE THE BARRIER! 5) On the data table, begin recording the temperature as soon as you turn off the switch (this will be start time 0). 6) Without stopping the timer, keep recording the air temperatures of the high temperature side, low temperature side, and the room temperature for the times listed in the table. 7) Graph the data as instructed. Answer the following questions based on your graph. Time Temp. of high side Temp. of low side Room temp. (Start time) 0 seconds 30 seconds 60 seconds 90 seconds 2 minutes 2.5 minutes 3 minutes 4 minutes 5 minutes 6 minutes 7 minutes 8 minutes 9 minutes 10 minutes 11 minutes 12 minutes 13 minutes 14 minutes 15 minutes 20 minutes 25 minutes Data Table: **After 15 minutes, you may begin plotting data on your graph. Making The Graph: 1) Put ALL 3 temperature sets on the SAME GRAPH. Use different symbols and/or colors to represent each set of data. 2) Time should be on the X-axis (bottom) and Temperature on the Y-axis (side). Be sure to LABEL each axis, include a key and a title!

12 p. 86 3) DRAW SMOOTH LINES THROUGH THE DOTS (i.e., connect the dots). Note: This graph is different from the straight lines you drew for the ping-pong ball graph. Patterns: Analysis: 1. Which chamber (high side or low side) was gaining energy during the first few minutes after the barrier was removed? Use your data to explain why you think so. 2. a) For how long (in minutes) was there a transfer of energy from one side to the other? b) At the start time of 0, what was the temperature difference between the high side and low side?

13 p. 87 c) At the end of the energy gained period, what was the difference between the high temperature and low temperature side? d) Between which times was the cooler side gaining energy the fastest? e) Using your knowledge of particle motion, explain why you think this is so. 3. At what time did the temperature on the low side begin to drop? What was the temperature of the high side at this time? What was the temperature of the low side? 4. Based on your data, which sides had the greatest temperature difference high side to low side or low side to room temperature? Why do you think so? 5. Explain why you think the high temperature side lost energy the whole time (you may want to draw a picture too). 6. Using your data and knowledge about particle motion, what conclusions and big ideas can you make about how energy moves between objects or from place to place? Explain.

14 IPS BB Lab p. 88 Purpose: To gather data about how the number of particles affects internal energy transfer. Materials/Procedure: 1) Measure 100 ml of tap water into a graduated cylinder. 2) Pour the water into the Styrofoam cup and record the starting water temperature (letter A in your data table) 3) Get the BB s from the hot water bath by your teacher. 4) Pour the BB s into the Styrofoam cup and carefully swirl the water with the thermometer until the temperature stops rising. BE CAREFUL NOT TO TOUCH THE BB s with the thermometer. Record the final temperature of the water (letter B in your data table). 5) Calculate the change in temperature of the water by subtracting the starting temperature from the final temperature. Record this in your data table (letter C). 6) Dump out the water and dry the BB s with a paper towel. 7) Go to a balance and get the mass of the BB s by pressing the TARE button and pouring them into the beaker that is on the balance. Record the mass in your data table (letter D). 8) Return the BB s to the test tube and put them back into the hot water bath. Be sure to catch any that have rolled away! Individual Group Data: A. Starting temperature of water before BB s B. Final temperature of water after BB s C. Change in temperature of the water D. Mass of BB s grams.

15 Class Data: Mass of BB s in grams 1a. 1b. 2a. 2b. 3a. 3b. 4a. 4b. 5a. 5b. 6a. 6b. Change in temperature of water in degrees Celsius p. 89 Making The Graph: Mass should be on the X-axis (bottom) and Temperature on the Y-axis (side). Be sure to LABEL each axis, include a key and a title! DRAW a line of best fit for the data. Change in temperature (Celsius) Mass of BB s (grams)

16 p. 90 Patterns: Questions: 1) If you have two amounts of BB s: 12 grams and 100 grams, both at the same starting temperature, and you dump them each into a cup of 100 ml of water, how will they affect the water s temperature and why? 2) Imagine you have a bathtub of water at a temperature of 0 C. You dump a cup of boiling water (100 C) into the bathtub. Predict what the final temperature of the water would be. Explain your prediction. 3) If you have a cup of hot chocolate and the MG pool, which one will have a higher temperature if we measure that right now? Use what you have learned to explain WHY. 4) Which one from #3 above will have a greater total amount of internal energy? Why?

17 IPS How Does it Feel Lab p. 91 Purpose: To compare how different materials feel in terms of temperature throughout the classroom and determine their temperatures. Procedure: You and your partner are to go around the room and touch various materials to determine their relative temperatures. You should touch at least 10 different materials and order them from coldest to warmest. After you and your partner have agreed on the order, get an LCT (liquid crystal thermometer) and measure the temperature of each material. You should have ten (10) materials. Ideas to test are: your desk top, leg of your desk, the floor, the bench top, wall, paper, window, wood cabinet, whiteboard, ceiling (if you check with you teacher first), periodic table, faucet, fume hood exterior, bulletin board, or any other item (please check with you teacher for other ideas). List the items you are going to test here. Data: List your ten items in order from coldest to warmest in the space below. You make your list and then check with you partner to see if you have the same order. After you have checked with your partner, get a LCT (liquid crystal thermometer) and measure and record the temperature of each material. Measured Temperature Coldest Warmest

18 p. 92 Pattern(s): 1. What is similar in your data in terms of which items felt coldest? 2. What is similar in your data in terms of which items felt warmest? 3. How do the recorded temperatures compare? Model Idea and Question: 1. Some object felt colder than others, while others felt warmer, even though they were the same temperature. Think of an explanation for this observation. 2. Why do you think metal containers are used to cook food on top of your stove? (think about what you want to heat up when you are cooking)

19 Measuring Internal Energy Notes p. 93 A. Units and symbols for internal energy 1. The symbol for internal energy 2. Common units for measuring internal energy a. calorie (cal) = b. Calorie (Cal) = c. calories = 1 Calorie B. Measuring change in internal energy 1. Calorimeter (a closed system) a. b. 2. Zero Law of Thermodynamics 3. First Law of Thermodynamics (Law of Conservation of Energy) C. What three things affect the amount of internal energy an object gains? INTERNAL ENERGY

20 D. What is Heat Capacity (Cp)? p Units of Cp= 3. In lab, you found that internal energy is transferred to some types of matter faster than it is transferred to others. This different rate (speed) of heat transfer is because of the heat capacity of the substance. Substance Heat Capacity (Cp) of some common substances Units of Cp= cal g C Alcohol (ethyl).581 Aluminum.214 Ammonia (liquid) Brass.09 Copper.092 Glass.199 Ice.5 Iron.107 Lead.031 Mercury.033 Platinum.032 Silver.056 Steam.48 Tungsten.034 Water (used as the standard) Zinc.093 E. Calculating internal energy 1. Equation Q = (internal energy gained or lost) 2. Internal Energy Triangle : Use this as an easy way to remember the internal energy equation F. Sample heat problem: A piece of metal was heated and transferred to a calorimeter cup. The cup contained 150 g of water that started at a temperature of 17 ºC. If the final temperature of the water was 25 ºC, how much heat (internal) energy (Q) did the metal transfer to the water?

21 Internal Energy Conceptual Practice Questions p. 95 Internal Energy 1. Use what you know about temperature and energy to explain why rubbing your hands together makes them warmer. 2. Suzi spent a winter afternoon outside building a snowman. She was outside so long that her hands got very cold. Explain why when she ran cold water on her hands the water felt hot. Change In Temperature 3. How come you can put ice in soda and it will make it colder? 4. Using what you learned about energy transfer in lab, explain why an ice cube in soup melts faster than an ice cube in soda. Mass 5. Explain why you don get burned by the sparks (1000 ºC) that shoot off from a sparkler, but why you would get really burnt if the sparkler wire (1000ºC) touched your arm. (Assume the amount of time these are both in contact with your skin are the same and assume that the temperature of the spark and the wire are the same when they hit your skin) g of Copper BB s were placed into 100 g of water at 25ºC. The water s temperature went down to 18ºC. What substance gained internal energy and what substance lost internal energy (the water or the BB s)? Explain your answer. Heat capacity 7. Winter coats are not made out of metal, other than the obvious reason that metal would be heavy and clunky, why don't we make clothing meant to keep us warm out of metal? 8. If we say something has a high heat capacity, what does that mean?

22 Additional Practice Questions p. 96 Answer the following question in complete sentences. When asked to estimate a temperature, do just that. In your response, make sure you clearly explain why you decided on that particular answer. 1) Bob has a cup full of 100ml of water that is at a temperature of 20 ºC. In another cup he has 100ml of water that is at 50 ºC. He pours the two together. What do you estimate will be the final temperature of the water? ºC. Use your model to explain WHY! 2) At a different table, Janie has a cup full of 100ml of water that is at a temperature of 20 ºC. In another cup she has 50ml of water that is at 50 ºC. She pours the two together. What do you estimate will be the final temperature of the water? ºC. Use your model to explain WHY! 3) Albert E. has a cup full of 100ml of water that is at a temperature of 20 ºC. In another cup he has 100ml of water that is at 20 ºC. He pours the two together. What do you estimate will be the final temperature of the water? ºC. Use your model to explain WHY! 4) Freidrich has a cup full of 100ml of water that is at a temperature of 20 ºC. He takes a bag from his freezer that is full of 50g of frozen peas at -10 ºC. He pours the peas into the cup of water. i) What do you estimate will be the final temperature of the water? ºC. Use your model to explain why. ii) What is the final temperature of the peas? ºC. Why?

23 IPS Internal Energy Calculations p. 97 Write out the equation for each problem then show your work as you use the equation. When you are finished be sure all the numbers have the proper units and you circle your answer. Use your Heat Capacity (C P) Chart in your notes in order to find the heat capacities you need. 1. A 50 g piece of silver was heated to 382ºC and then placed into 200 g of water at 20ºC. The final temperature of the water was 25ºC. a. Fill out the following information with UNITS: Water Data Silver Data Mass of water = Mass of silver = Initial temp water = Initial temp silver = Final temp water = Final temp silver = b.using the data from the table above, determine the change in temperature ( T) for the water and the silver. Make sure to show your work!! Water s change in temperature ( T) Silver s change in temperature ( T) c.determine if the water gained internal energy (had internal energy transferred to it) or lost internal energy (transferred internal energy to something away) then do the same for the silver: Water Silver d.explain how you know if an object is gaining or losing internal energy? e.calculate the amount of internal energy gained by the water, and the amount of internal energy lost by the silver (transferred to the water). Make sure to show your equation and then substitutions. Q gained by the water = Q lost by the silver =

24 p a.an object that is made of iron has a mass of 500 g. It is heated to a temperature of 1200ºC and then cooled in water to a temperature of 50ºC. Is the iron gaining or losing heat energy? How do you know? b.determine how much internal energy was lost by the iron. (You might want to list the variables, just like in class first, then figure out the answer.) c.determine how much internal energy was gained by the water. How do you know? 3. a.an object made of brass was heated to a temperature of 850ºC and then put into a calorimeter. The water temperature after the hot brass was placed in the water was 40ºC. If the brass had a mass of 100 g, how much internal energy did the brass transfer or lose to the water? b.how much internal energy did the water gain (from the brass)? How do you know? 4. a.a piece of platinum was placed into a calorimeter. The calorimeter contained 150 g of water with an initial (starting) temperature of 17ºC. The final temperature of the water was 25ºC. Determine the amount of internal energy the water gained. b.how much internal energy did the platinum lose (transfer to the water)? 5. A piece of gold was placed into 100 g of water at 23ºC. The final temperature of the water ended up being 23ºC. How much internal energy was gained by the water? How do you know?

25 Conduction, Convention, and Radiation p. 99 Conduction Activity: Feel the different spoons in the ice bath, in your observations make note of how each spoon feels. Observations: Reading: Conduction is the transfer of energy through matter from particle to particle. It is the transfer and distribution of heat energy from atom to atom within a substance. For example, a spoon in a cup of hot soup becomes warmer because the heat from the soup is conducted along the spoon. Conduction is most effective in solids-but it can happen in fluids. Fun fact: Have you ever noticed that metals tend to feel cold? Believe it or not, they are not colder! They only feel colder because they conduct heat away from your hand. You perceive the heat that is leaving your hand as cold. Convection Activity: Lower the warm colored water into the container of cold water, take the stopper out of the warm water, and watch what happens. Record your observations below. Observations: Reading: Convection is the transfer of heat by the actual movement of the warmed matter. Heat leaves the coffee cup as the currents of steam and air rise. Convection is the transfer of heat energy in a gas or liquid by movement of currents. (It can also happen is some solids, like sand.) The heat moves with the fluid. Consider this: convection is responsible for making macaroni rise and fall in a pot of heated water. The warmer portions of the water are less dense and therefore, they rise. Meanwhile, the cooler portions of the water fall because they are denser.

26 Radiation p. 100 Activity: Measure the temperature of the black and white cans exposed to the light bulb. Record the data on the sheet by the cans. At the end of class be sure to observe the results of both cans and record your observations below. Observations: Reading: Radiation is electromagnetic waves that directly transport ENERGY through space. Sunlight is a form of radiation that is radiated through space to our planet without the aid of fluids or solids. The energy travels through nothingness! Just think of it! The sun transfers heat through 93 million miles of space. Because there are no solids (like a huge spoon) touching the sun and our planet, conduction is not responsible for bringing heat to Earth. Since there are no fluids (like air and water) in space, convection is not responsible for transferring the heat. Thus, radiation brings heat to our planet. Pull It All Together Design a good insulating mug to keep hot chocolate warm, be sure to address how you dealt with all three manners of transferring energy. Draw a picture of the final product as well as include a written explanation about why you choose the parts you did. Make sure you address conduction, convection and radiation in your design!

27 p. 101 IPS More Internal Energy Practice Problems Write out the equation for each problem then show your work as you use the equation. When you are finished be sure all the numbers have the proper units and you circle your answer. Use your Heat Capacity (C P) Chart in your notes in order to find the heat capacities you need. 1. A very hot object transferred 500 cal to water and the T of the water was 4ºC. If this happened, determine the mass of the water g of water initially that started at 20ºC gained 4000 cal. Calculate the final temperature of the water. (Hint: You might want to find T first) 3. Some Tungsten (another metal) starting at 300ºC was cooled in some water to 50ºC. The water that cooled the metal gained 2000 cal. a. How much internal energy did the Tungsten lose? How do you know? b. What was the mass of the Tungsten that was cooled? 4. A piece of mystery metal with a mass of 50 g was heated to 117.5ºC. The hot metal was transferred to a calorimeter containing 250 g of water at 20ºC. The final temperature of the water was 24ºC. a. What were the T s for the water and the metal? Water= Metal = b. How much internal energy did the water gain? c. How much internal energy did the metal lose? d. What is this mystery metal? (Hint: If you find the C P of the metal, you ll know what metal it is!)

28 IPS Counting Calories Lab p. 102 Purpose: Materials: Procedure: To make quantitative observations during the burning of various foods, and using our model of matter and thermodynamic laws, calculate the amount of internal energy certain foods can transfer to water or people. various burnable foods and nutrition labels; cork/needle combo; candle; electronic balance; test tube; water; test tube holder; thermometer 1. Calculate the Calories per gram of the food based on its nutrition label in your data table. 2. Mass food and cork/needle combo before burning. RECORD in your data table. 3. Measure 8-10 ml of water and RECORD EXACTLY how much you have in your data table and transfer to a test tube. 4. Determine the initial (starting) temperature of the water. RECORD in your data table. 5. Light food on fire, place cork/needle combo on bench top and hold test tube with test tube holder directly above the burning food. 6. Monitor temperature of water and RECORD highest temperature the water reaches in your data table. 7. Carefully carry cork/needle combo with burned food to balance and RECORD mass after burning in your data table. 8. Calculate the calories gained by the water in your data table. Make sure to show your work! 9. Determine the Calories transferred by the food in your data table. Make sure to show your work! 10. Determine the amount of food burned. Make sure to show your work! 11. Calculate the Calories per gram of the food based on your lab data and record in your data table. Make sure to show your work! 12. Get your teacher to sign off on your calculation and prepare to test another food item. 13. Clean up in preparation for the next food item; throw away the burned food and use a dry paper towel to wipe test tube clean before next sample.

29 Data: p. 103 Food #1 Food Type Nutrition Label Information Serving Size: grams Calories per serving: Calories Calories per gram: Water Data Mass of water: g Initial temperature of water: C Final Temperature of water: C T = C Q gained by water ( little calories ) Q = m* T*Cp Q = Food Data Mass of food and cork before burning: g Mass of food and cork after burning: g Total grams of food burned = g Q lost by food( Big Calories ) Equal to Q gained by water Convert from cal to Cal (divide by 1000) Q in food = Cal Calories per gram by our calculations: Were you close? Teacher sign off:

30 p. 104 Food #2 Food Type Nutrition Label Information Serving Size: grams Calories per serving: Calories Calories per gram: Water Data Mass of water: g Initial temperature of water: C Final Temperature of water: C T = C Q gained by water ( little calories ) Q = m* T*Cp Q = Food Data Mass of food and cork before burning: g Mass of food and cork after burning: g Total grams of food burned = g Q lost by food( Big Calories ) Equal to Q gained by water Convert from cal to Cal (divide by 1000) Q in food = Cal Calories per gram by our calculations: Were you close? Teacher sign off:

31 p. 105 Food #3 Food Type Nutrition Label Information Serving Size: grams Calories per serving: Calories Calories per gram: Water Data Mass of water: g Initial temperature of water: C Final Temperature of water: C T = C Q gained by water ( little calories ) Q = m* T*Cp Q = Food Data Mass of food and cork before burning: g Mass of food and cork after burning: g Total grams of food burned = g Q lost by food( Big Calories ) Equal to Q gained by water Convert from cal to Cal (divide by 1000) Q in food = Cal Calories per gram by our calculations: Were you close? Teacher sign off:

32 Change of State Data Collection p. 106 Use the data table below to collect temperature data and observations of what happens when ice is heated for 25 minutes. Be sure to make detailed observations about the state or states of matter you see in the beaker. Time Temperature Observations/ Time Temperature Observations/ State of matter State of matter 0 min 10.5 min 0.5 min 11 min 1 min 11.5 min 1.5 min 12 min 2 min 12.5 min 2.5 min 13 min 3 min 13.5 min 3.5 min 14 min 4 min 14.5 min 4.5 min 15 min 5 min 15.5 min 5.5 min 16 min 6 min 16.5 min 6.5 min 17 min 7 min 17.5 min 7.5 min 18 min 8 min 18.5 min 8.5 min 19 min 9 min 19.5 min 9.5 min 20 min 10 min 25 min

33 Excel Graphing Instructions p. 107 Step 1: Step 2: Step 3: Step 4: Step 5: Step 6: Step 7: Step 8: Step 9: Step 10: Open Excel You should find it under the start icon on the menu bar at the bottom of your screen. Enter your data in columns Once Excel is open and you have a new spreadsheet, you are ready to enter your data. Use headings for each column to label the data listed. Remember to use units on all labels. You can take a few minutes to make it look nice. Highlight your data to be graphed Make sure you highlight the headings at the top of your columns in addition to the data in the columns. Click on the Chart Wizard Icon The Chart Wizard Icon is on the top tool bar and looks like a 3-d bar graph. Choose the type of graph you want You have lots of choices, but for our purposes in this class, you will want to use the chart type XY (Scatter) from the list on the left. Once you do this you will get to pick between five different chart sub-types. You should select the sub-type that does not have any lines in it (By the way, this is the sub-type that is pre-selected, so you shouldn t have to do anything.) Now click Next>. Click Next> to skip Step 2 of 4 Chart Source Data Later when our work gets more involved, we will use this step. But for now, please just select next. You can look at what you could do with this one. That is up to you. Step 3 of 4 Chart Options Do lots here!! Title: Give your chart a title by clicking in the box labeled chart title. Please enter a name for your graph. Be sure to include YOUR NAME in the title. Still under the title tab, click on the box that says Value (X) Axis and enter a label WITH UNITS for that axis. Do the same for the Y-axis. Add appropriate grid lines; choose a legend (but only if you are graphing more than 1 set of data); data labels are normally not needed, but you can play with this one if you d like to. When done, click Next>. Step 4 of 4 Chart Location Give your Graph a name and save it Click on the bubble to save your chart as a new sheet. Give it a name, and click Finish. Double-click on the gray background color on your graph and change the color to white When you do this, you get a color window. Click on the white square and then OK. Double check the following before you print your graph Make sure you have: A title Labeled axis with appropriate units Make sure the background of your graph is WHITE (let s not waste printer toner!!)

34 Change of State Graph Observations p. 108 Once you have printed your graph please use it to answer the following questions: 1. Describe what patterns you see in the graph. Be sure to explain all that you see in the graph and use complete sentences. 2. At what time did that water start to melt? 3. At what time was all the water melted? 4. How long did it take for all of the ice to melt? 5. At what time did the water start to boil? 6. What do you think would happen if we continued heating the water for more than 20 minutes? Explain why you think that might happen. 7. Now look at the graph your teacher handed out, what do you notice is the same in both data sets? 8. Now look at the graph your teacher handed out, what do you notice is different in both data sets?

35 Change of State Notes p. 109 You saw in the demonstration in class that it takes energy to melt ice. You also saw that the same patterns that you observed in your graph for the change of state of water in the graph of the change of state of ethanol. What is going on to make both of these behave similarly? It all has to do with something called the change of state. Internal energy associated with change of state: 1. Heat of fusion (H f) Definition: 2. Heat of Vaporization (H v)- Definition : 3. Significance of a change of state:

36 IPS Internal Energy Review p What did we learn in the following labs: a. Moving Particles Lab b. Hanger Lab c. Transimeter Lab Make sure to look at your lab!! d. BB lab Make sure to look at your lab!! e. How does it feel lab 2. Write the symbol and units for the following quantities a. Temperature: symbol units b. Changing in temperature: symbol units c. Internal energy: symbol units d. Mass: symbol units e. Heat capacity: symbol units 3. Define what energy is 4. What is kinetic energy? 5. What is potential energy?

37 p What does temperature mean in terms of particles? 7. Convert the following temperatures. If you are given C, convert to F and if you are given F convert to C. a. 147 C b. 13 C c. 56 F d. 45 F 8. Define the following: a. 0 Law of Thermodynamics b. 1 st Law of Thermodynamics 9. When you put ice in your room temperature soda which of the objects is gaining energy? Which is losing energy? How can you tell? 10. What are the three ideas that affect how much internal energy an object can gain or transfer? (1) (2) (3)

38 p Your friend is on the Who Wants to be a High School Millionaire game show and uses a lifeline to call you with this question: If a hot piece of metal transfers 1000 calories of heat energy to H 2O in a calorimeter, how many Calories did it transfer? a Cal b. 252 Cal c Cal d. 1 Cal b. Explain your answer. 12. You have two objects. Object A has a mass of 100 grams and is at a temperature of 20 C. Object be has a mass of only 10 grams and is at a temperature of 50 C. a. Explain whether or not there will be a transfer of internal energy between objects A and B. b. Explain which object will be gaining internal energy. 13. Define Conduction. 14. Define Convection. 15. Define Radiation. 16. A silver ring with a mass of 75 grams transferred 1500 cal to some water. The final temperature of the water was 25 C. What was the change in temperature of the metal and for a little harder question, what was the starting temperature of the silver? C P silver = cal o g C. Please fill in the appropriate spaces before solving this problem. m = T = C P = Q =

39 p You burned a piece of pop-tart during the food lab and found its mass before burning to be 12.2g. After holding the test tube of 10g of H 2O over the burning tart you know the temperature of the H 2O rose from 22 º C to 77 ºC. The burnt pop-tart weighed 9.1g a. How much internal energy was lost by the burning pop-tart? b. Convert this answer to Calories. 18. You are making pizza on your aluminum pizza pan of mass 200g. Once the oven and pan are preheated to 170ºC you know you are ready to put the pizza on the pan. If the pan started out at a room temperature of 25ºC, how many calories of internal energy were transferred from the oven to the pan? Please fill in the appropriate spaces before solving this problem. m = T = C P = Q = 19. Explain why there is no change in temperature when an object is changing from a solid to a liquid. 20. On the graph below label where you would find a solid, liquid, and gas as well as where the changes in phase would be located. Temperature Time (increasing Internal Energy)