General Start-up Procedure:
? Prior to running an experiment. pupils are advised to execute the undermentioned startup process.
? Fill the H2O with clean ( sooner filtered ) H2O to about 20 millimeter from the top.
? Plug the chief overseas telegram to the electrical supply. Be certain that the electromotive force of the supply is right to suite the equipment.
? Switch on the chief power on the control panel.
? Adjust the set-point value on the temperature accountant to 500C.
Warning! !
Do non put the temperature accountant beyond 700C.
Switch on the warmer. Detect the H2O temperature heats up to 50 0C and stay changeless.
The equipment is now ready for experiment.
Priming process for capillary Tube:
Before utilizing the capillary tubing in an experiment utilizing propanone. pupils are advised to clean the interior of the tubing.
? Prepare a weak solution of detergent.
? Use the Hirschman pipette to make full the tubing with the solution. Taping the of side of the tubing may be necessary if the solution is trapped and does non flux down.
? Turn the tubing inverted and agitate. Empty the tubing.
? Repeat stairss 2 to 3 with propanone.
? The tubing is now ready for student experiment.
General Shut-down Procedure:
? After the completion of an experiment. pupils are advised to close down the equipment as follows:
? Switch off the warmer and air pump.
? Adjust the set-point value of the temperature accountant to about 5 grade below the room temperature.
? Let the H2O to chill down until it is safe to touch. Open the drain valve and empty the H2O armored combat vehicle.
? Detach the flexible tube and clean the capillary tubing for following usage. ( Refer to priming process )
? Switch off the chief power. Unplug the chief overseas telegram if the equipment will non be used for a long period.
Experiment
Aim:
To find gas diffusion coefficient of propanone utilizing the established Winkelmann’s method.
Procedure:
1. Perform the start-up process.
2. Partially fill the capillary tubing with propanone to a deepness of about 35 millimeters.
3. Carefully insert the capillary tubing through the adjustment on the top of the H2O bath screen. Make non over-tighten the adjustment.
4. Detect the initial degree of propanone through the telescope. Record the degree of propanone.
5. Connect the flexible tube from the air pump line to one terminal of the capillary tubing. Switch over on the air pump.
6. After 30 proceedingss. exchange off the air pump. Unplug the flexible tube and shut the two capillary tubings ends with the cap provided. Observe and enter the degree of propanone.
7. Repeat steps 4 to 6 at 30 proceedingss intervals.
ANALYSIS & A ; DISCUSSION:
Plot t/ ( L-L0 ) against ( L-L0 ) . Determine gas diffusivity. D from the obtained incline. S. Compare the experimental value with the theoretical value that can be predicted from empirical equations ( e. g. modified Maxwell’s equation by Gilliland ) .
