12
specific latent specific latent heat of heat of vaporization of vaporization of water water B B y Ellie y Ellie

A2/ Expt /Thermal/ Ellie

Embed Size (px)

DESCRIPTION

 

Citation preview

Page 1: A2/ Expt /Thermal/ Ellie

specific latent heat of specific latent heat of vaporization of water vaporization of water

BBy Elliey Ellie

Page 2: A2/ Expt /Thermal/ Ellie

diagramdiagram

Page 3: A2/ Expt /Thermal/ Ellie

previewpreview

Use a Fast-Response Temperature Probe to measure the change in temperature of a known mass of water as steam changes from gas to liquid in the water.

Use the Xplorer GLX to record and display the temperature. Determine the latent heat of vaporization of the steam.

Page 4: A2/ Expt /Thermal/ Ellie

EEquipment Setupquipment Setup

Set up a PASCO Steam Generator with a Set up a PASCO Steam Generator with a water trap and plastic tubing as shown. Put a water trap and plastic tubing as shown. Put a glass tube in the end of the piece of plastic glass tube in the end of the piece of plastic tubing that will go into the calorimeter.tubing that will go into the calorimeter.

Fill the generator about two-thirds full of Fill the generator about two-thirds full of water and turn on the generator to “HIGH”. water and turn on the generator to “HIGH”. Adjust the height of the water trap if Adjust the height of the water trap if necessary.necessary.

Measure and record the mass of a Measure and record the mass of a calorimeter from the PASCO Basic calorimeter from the PASCO Basic Calorimetry Set.Calorimetry Set.

Page 5: A2/ Expt /Thermal/ Ellie

Fill the calorimeter approximately half-full Fill the calorimeter approximately half-full of cool water (about 10º C below room of cool water (about 10º C below room temperature).temperature).

Measure and record the mass of the Measure and record the mass of the calorimeter plus water.calorimeter plus water.

Wait until the steam flows freely for at Wait until the steam flows freely for at least a minute, and then get ready to start least a minute, and then get ready to start recording data.recording data.

Page 6: A2/ Expt /Thermal/ Ellie

Record DataRecord Data1.1. Press Start ( ) on the GLX to Press Start ( ) on the GLX to

measure the signal from the measure the signal from the Temperature Probe.Temperature Probe.

The temperature appears in the The temperature appears in the graph display. Make a note of the graph display. Make a note of the initial temperature of the water.initial temperature of the water.

2.2. Immerse the end of the tube from Immerse the end of the tube from the steam generator into the cool the steam generator into the cool water in the calorimeter. Gently water in the calorimeter. Gently swirl the water in the calorimeter.swirl the water in the calorimeter.

Page 7: A2/ Expt /Thermal/ Ellie

3.3. Carefully watch the temperature in Carefully watch the temperature in the Graph screen. When the water the Graph screen. When the water temperature gets as far temperature gets as far above above room room temperature as it was initially temperature as it was initially below below room temperature, remove the room temperature, remove the steam tube from the water and turn steam tube from the water and turn off the generator.off the generator.

4.4. Continue to record data and to swirl Continue to record data and to swirl the water until the water the water until the water temperature reaches its highest temperature reaches its highest value and begins to drop.value and begins to drop.

Page 8: A2/ Expt /Thermal/ Ellie

5.5. Press to stop data recording.Press to stop data recording.

6.6. Remove the Temperature Probe Remove the Temperature Probe and then immediately measure and and then immediately measure and record the mass of the calorimeter record the mass of the calorimeter plus water plus condensed steam.plus water plus condensed steam.

7.7. Clean up the equipment as Clean up the equipment as instructed.instructed.

Page 9: A2/ Expt /Thermal/ Ellie

MMethod ethod Use the graph of temperature versus time Use the graph of temperature versus time

to find the initial temperature of the water to find the initial temperature of the water and the equilibrium temperature, or final and the equilibrium temperature, or final temperature, of the water and the temperature, of the water and the condensed steam.condensed steam.

Press F3 ( ) to open the ‘Tools’ menu. Select Press F3 ( ) to open the ‘Tools’ menu. Select ‘Smart Tool’. Use the arrow keys to move ‘Smart Tool’. Use the arrow keys to move the cursor to the part of the graph that the cursor to the part of the graph that shows the initial temperature of the water. shows the initial temperature of the water. Record the value.Record the value.

Repeat the process to find the final Repeat the process to find the final temperature (equilibrium temperature) of temperature (equilibrium temperature) of the water and the condensed steam.the water and the condensed steam.

Page 10: A2/ Expt /Thermal/ Ellie

Use your measurements of the mass Use your measurements of the mass of the calorimeter, the calorimeter of the calorimeter, the calorimeter plus water, and the calorimeter plus plus water, and the calorimeter plus water plus steam to determine the water plus steam to determine the mass of the water and the mass of the mass of the water and the mass of the condensed steam.condensed steam.

Use the mass of the water, the mass Use the mass of the water, the mass of the steam, and the initial and final of the steam, and the initial and final temperatures of the water to calculate temperatures of the water to calculate the heat of vaporization of water.the heat of vaporization of water.

Page 11: A2/ Expt /Thermal/ Ellie

Safety Precaution

Follow all directions for using the equipment. Be very careful around the Steam Generator.

Wear protective gear (such as gloves, goggles, and lab coat.)

Page 12: A2/ Expt /Thermal/ Ellie

RReduce erroreduce error

CCheck the equipment before start the heck the equipment before start the experiment to reduce system error. experiment to reduce system error. E.g: zero-error.E.g: zero-error.