Name: Per.: Date: Calorimetry Lab Purpose to determine the amount of Calories in a cheese puff. In this experiment, you will be investigating the transfer of heat energy from a burning cheese puff to cool water. The cool water will gain heat lost by the cheese puff until thermal equilibrium is attained. Pre-lab Questions 1-10: Use complete sentences when applicable. 1. Hypothesis: 2. Define heat and explain how heat is transferred between objects. List some units of heat explain the relationship between units. What type of energy is heat? 3. Define thermal equilibrium 4. What is the difference between an endothermic and exothermic reaction? Give an example of each one. 5. Define calorimetry and explain how a calorimeter is used to determine the energy value in food. 6. Record the formula for heat (Q). Label and define units of measure.
7. @ class: Solve the following calorimeter problem. Show all of your work. A sample of Fritos weighing 1.256 g was combusted in a calorimeter but not the entire sample burned. The mass of the Fritos sample after combustion was.6314g the calorimeter was filled with 150.0 ml of water, the initial temperature of the water before combustion was 25.0 degrees Celsius, after combustion the temperature of the water was 41.2 degrees Celsius. Find the Calories per gram in a Frito and compare this to the nutritional label on a bag of Fritos. The nutritional label on a bag of Fritos: 150Cal/28g. Solve for percent error. Record the specific heat for water in calories (small c)/g x C 8. Solve the problem below and show all of your work. 7.00 grams of sucrose was combusted in a calorimeter. The calorimeter was filled with 1500.0 grams of water; the initial temperature of the water before combustion was 25.0 degrees Celsius, after combustion the temperature of the water was 41.24 degrees Celsius. After combustion the sugar weighed 0.0479g Find the Calories in a gram of sugar and compare this to the nutritional label on a bag of sugar. The nutritional label on a bag of sugar records 15Cal/4grams. Solve for percent error. 9. List the steps for lighting and turning off a Bunsen burner include all safety rules. 10. READ and highlight the lab procedure.
Complete Trial 1 and calculate trial 1 data. Record all quantitative data in the tables below. Show your work for all calculations. All quantitative data must be followed by a unit and be recorded in significant figures. In the lab you will be collecting quantitative and qualitative data. Compare and contrast these two types of data. What kind of qualitative data will you collect? Data Table: Trial: 1 2 3 1 2 3 1 2 3 Before Burning After Burning Difference Mass of cheese puff and paper clip In grams Temperature of Water in C Volume of water in Calorimeter (pop can) ml Remains the same before and after burning Not applicable Calculations for Trial 1: Show all your work. Use UNITS and SF. 1. Calculate heat (Q) for the water using the heat equation. Record the Q equation, plug in data from trial 1, and solve for heat. 2. Calculate the calories (small c calorie) per gram in the cheese puff. Q water /grams of cheese puff burned. 3. Calculate the Calories per gram in the cheese puff. Convert small c calorie to big C. 1000 calories = 1 Calories
Record the %error formula: 4. Determine the percent error for trial 1. Cheddar cheese puffs nutrition label reads: 160 Calories/28 grams-accepted value. Show your work below. 5. Analyze the results of trial 1 for accuracy. Did trial 1 show poor, OK, or Good accuracy? 6. Discuss and record experimental error below. What improvements could be made before you complete trial 2? C/g in the Cheetos Measured Value Trial 1 Trial 2 Trial 3 % Error Trial 1 Trial 2 Trial 3 Conclusion: Include the following information in your conclusion: -Accept or reject your hypothesis based on the data - What did you learn from doing this experiment? -After analyzing your data what can you conclude about the cheese puff. - Analyze your data and compare your measured value for the amount of Calories per gram of cheese puff to the Actual Value found on the bag of cheese puffs -How accurate was your experiment? -Make an error analysis and account for any differences between your measured value and the accepted value. - Compare your makeshift calorimeter to the bomb calorimeter.
Calculations for Trial 2: Show all your work. Use UNITS and SF. 1. Calculate heat (Q) for the water using the heat equation. Record the Q equation, plug in data from trial 2, and solve for heat. 2. Calculate the calories (small c calorie) per gram in the cheese puff. Q water /grams of cheese puff burned. 3. Calculate the Calories per gram in the cheese puff. Convert small c calorie to big C. 1000 calories = 1 Calories Record the %error formula: 4. Determine the percent error for trial 2. Cheddar cheese puffs nutrition label reads: 160 Calories/28 grams-accepted value. Show your work below. 5. Analyze the results of trial 2 for accuracy. Did trial 2 show poor, OK, or Good accuracy? How does trial 1 compare to trial 2 for precision. Explain the terms accuracy and precision.