Lab 10

Page 1 Names: PHYSICS 1020 LAB: Temperature and Heat Part I: HEAT OF FUSION DATA PAGE FOR THE HEAT OF FUSION LAB mass of cup (kg) m cup   mass of cup + water (kg) m cup + m w   mass of cup + water + ice (kg) m cup + m w + m ice   mass of water (kg) m w   mass of ice (kg) m ice   initial temperature of water ( o C) T i   final temperature of water ( o C) T f   latent heat of fusion (J/kg) L f (measured)   latent heat of fusion (J/kg) L f (accepted)   3.33 × 10 5 J / kg Question 1: In order for the ice cube to melt, it has to extract heat energy from the warmer water, first a small amount of heat to warm up to 0°C, then a larger amount to melt. The melting ice absorbs heat energy, and thus cools the water. The heat energy absorbed per gram when a substance changes from a solid to a liquid is called the heat of fusion. How is the amount of heat energy absorbed by the solid related to the heat of fusion and the mass of the solid? Question 2: The total amount of heat energy lost by the water is equal to the amounts of heat energy it took to do what things? Question 3: What are some sources of error in this experiment? Part II: HEAT MIXES Measuring Heat Lab The heat absorbed is directly proportional to both the mass of the solid and the heat of the fusion. Raise its temperature and undergo the phase changes. Styrofoam could be morphed or something during the experiment or the scale might be wrong.

Page 2 Data: (Remember to write correct units!!) Mass 1.0 kg 3.0 kg Initial temperature 100 o C 160 o C Specific heat capacity 4.40 x 10 5 J/(kg o C) 0.7333 x 10 5 J/(kg o C) Final temperature 120 o C 120 o C ΔT +20 o C -40 o C Results: 1. Calculate the heat lost by the hot water. Remember to write the units !! Q for hot material Q = 3kg .7333x10^5 J -40 x C p Q = -8.8 x 10^6 Jouls 3. Calculate the heat gained by the cold water. Remember to write the units !! Q for cold material Q = 1kg 4.40 x 10^5 J 20c x C p Q= 8.8 x 10^6 Jouls Question 4: What is the difference (in Joules) in the amount of heat lost by the hot material and the amount of heat gained by the cold material? Question 5: How do you explain any differences? In other words, this amount of heat did not get transferred from the hot water to the cold water. What happened to it Question 6: Suppose you were to drop a very hot quarter into a cup of cold water. Describe the energy transfer that would take place Sample The hot material lost -1.76x10^7 J than the cold material gained. Heat losses to Surroundings and incomplete thermal contact. Conduction and Convection would take place as heat moves from the hot quarter to the cold water.