University:
Widener University
Course:
1046C | General Chemistry
Academic year:

2019
Views:

201

Pages:

2
Author:

J Clay

Calorimetry What is the relationship between heat energy and temperature? Why? When a substance is heated, the temperature of that substance increases. Will the same amount of energy cause different substances to have identical temperature increases? Will the same amount of energy be needed to cause identical temperature increases in different amounts of the same substance? In this activity you will explore how mass, temperature, heat energy, and the type of substance are related. Model 1 – A Pot of Water Before heating 4 qt. saucepan 8 qt. stockpot 24.5 °C Temp. 24.5 °C Temp. After heating for 5 minutes at a rate of 30 Joules per minute 4 qt. saucepan 24.5 *C 8 qt. stockpot Temp. 24.5 *C Temp. 1. In Model 1, which container holds more grams of water? The 8 qt. stockpot 2. Consider the process described in Model 1: a. How many joules of energy were added to the saucepan? 150 Joules b. How many joules of energy were added to the stockpot? 150 Joules c. In which container did the liquid gain more energy or did both gain the same amount? Explain your reasoning. They gain the same because they are being heated at the same rate for the same time. d. For each container, include whether the temperature is expected to increase, decrease or remain the same after heating. Explain your reasoning. It should increase because it is being heated and more energy is being added. Model 2 – Experimental Data for Heating Water Experiment 1 Trial A B C D E F Mass (g) 1.00 2.00 2.50 3.00 3.50 4.00 ΔT (°C) 26.8 13.4 10.7 8.93 7.66 Mass (g) 3.00 3.00 3.00 3.00 3.00 3.00 ΔT (°C) 3.00 6.00 9.00 12.0 15.0 18.0 Added Energy (Joules) 37.6 75.2 113 150 188 Mass (g) 1.00 2.00 2.50 3.00 3.50 4.00 ΔT (°C) 9.00 9.00 9.00 9.00 9.00 Added Energy (Joules) 37.6 75.0 94.1 113 132 150 6.70 Added Energy (Joules) 112 112 112 112 112 112 Experiment 2 Trial A B C D E F 226 Experiment 3 Trial A B C D E F 8.97 3. In the data tables in Model 2, what does ΔT mean? Change in Temperature 4. Which experiment in Model 2 illustrates how the amount of energy needed to achieve the same temperature change depends on the mass of water? Experiment 3 5. Which experiment in Model 2 illustrates how different amounts of energy result in different temperature changes when the mass of water is constant? Experiment 2 6. Why was it necessary to perform three experiments to find the relationships between mass, temperature change, and energy? So that we understand how energy affects temperature and vice versa.