a) Define heat capacity. b) Describe an experiment to determine the specific latent heat of steam.

Here's the solution to question 13. Question 13: a) Define the term heat capacity. Heat capacity is the amount of heat energy required to change the temperature of a body by one degree Celsius (or one Kelvin). b) Describe an experiment to determine the specific latent heat of steam, using the set up in Fig 5 and stopwatch. Clearly explain the measurements to be made and how these measurements could be used to determine L_v (latent heat of vaporization). Experiment Description: 1. Place a known mass of water in a lagged calorimeter (to minimize heat loss). 2. Immerse an electric heater of known power P and a thermometer into the water. 3. Heat the water to its boiling point (100\,^C). 4. Once the water is boiling steadily, use the scale balance to record the initial mass of the calorimeter and its contents (m_1). 5. Simultaneously start the stopwatch and allow the water to boil for a measured time t, during which steam escapes. 6. After time t, switch off the heater and stop the stopwatch. 7. Immediately record the final mass of the calorimeter and its contents (m_2) using the scale balance. Measurements to be made: Initial mass of the calorimeter and water, m_1 (in kg). Final mass of the calorimeter and water, m_2 (in kg). Time of heating, t (in seconds). Power of the electric heater, P (in Watts). Calculation of L_v: 1. The mass of steam evaporated during the time t is calculated as the difference between the initial and final masses: m = m_1 - m_2 2. The electrical energy supplied by the heater during this time is given by: Q = P × t 3. Assuming that all the electrical energy supplied is used to vaporize the water (due to the lagging), the heat supplied is equal to the heat absorbed by the steam: Q = m L_v 4. By equating the two expressions for Q, we can determine the specific latent heat of vaporization, L_v: P × t = (m_1 - m_2) L_v L_v = (P × t)/(m_1 - m_2) The unit for L_v will be Joules per kilogram (J/kg). That's 2 down. 3 left today — send the next one.