TABLE OF CONTENT General Instructions Experiment 1 Experiment 2 Experiment 3 Experiment 4 Experiment 5 Experiment 6 Isentropic Expansion Process Brief Depressurization The Fundamental Pressure-Temperature Relationship of Saturated Steam in Equilibrium Determination of Ratio of Volume Determination of Ratio of Heat Capacity Demonstration of Vapour Compression Refrigeration Cycle APPENDIX A Perfect Gas Expansion Unit B Marcet Boiler OpenEnded
GENERAL INSTRUCTIONS Laboratory experiments are designed with the intention of being completed during the allotted classroom time. In order to expedite things it is mandatory that you be prepared prior coming to the lab. This includes reading the lab procedure handout thoroughly and understanding the experiments illustrations and techniques. In additional, any applicable calculations (such as solution
preparations) should be made in advance so that work may commence upon arriving in the lab. A flowchart of the experiment methodology is helpful in determining what steps should be taken and the order in which things must be done. In addition, it is important that you familiarize yourself with lab techniques learned in your chemistry classes.
Some experiments may take longer that the others, but the biggest determinant will be your preparation.
ATTENDANCE IS MANDATORY!
You are required to have a logbook. This must be a bound logbook. It is very important to get into a habit of writing a logbook. You are required to translate the procedure of each lab in the lab manual into graphical illustration or flowchart in your logbook before you begin your experiment. Recording in the logbook should be written as the experiment is carried out and should be as brief, but concise, as possible. Record in your logbook everything you do and observe as you carry out the experiment.
Each experiment in the logbook should contain the following information:
(i) (ii) (iii) (iv) (v) (vi)
Title of the experiment Date of the experiment carried out Objective of the experiment Hypothesis of the experiment Procedure outline or brief description of the method Observation (should be recorded throughout the experiment)
A logbook should be neat. Clarification of procedure and results are important. Always use a pen to write your logbook. For any mistake or changing of the data written on the logbook, the usage of liquid paper or eraser is not allowed. Always use a pen to cross out if any errors. The lab instructor/lecturer will inspect and sign your logbook during the lab session and possibly grade them at the end of the semester.
You will be assigned to a lab group (please refer to the student notice board or outside the lab after the first session of the laboratory meet up). Students are not allowed to change their team member for lab. You are required to work with you group members as much as possible in terms of understanding the lab work and sharing information on the different sections that were performed by different members.
Report must be submitted one week after the scheduled experiment and within the 1st 10 minutes of the due lab period. Marks would be deducted accordingly for late reports or may not be accepted. Students who caught blatantly copying from other or involved in any plagiarism activities will be required to resubmit their work, or otherwise zero marks will be given.
Lab report must be in hand written or typed. Each of the group members must contribute in the report. Report should contain the following:
Front page (refer the at Appendices A) Table of content Objective Introduction/background of the experiment Material and Methodology Results and discussion Conclusion Limitation of the Experiment Reference Appendix (if any)
Lab reports are to be assembled in a logical and orderly way. Tedious calculations must be placed in sequential order in the report. The report shall be:
Written in passive tense. Example: “Five milligram of solid was weighted.”
Graph must be with title, axis labels with units and legend when necessary. The scale of the graph should be adjusted to fit the graph data.
Plagiarism will not be allowed and tolerated. Use suitable analysis method during explanations for the graph such as R-value, slope of the line, line equations, etc in explaining the experiment.
Only chemical compound structures can be drawn using handwriting.
Report outlines and marks distributions: Introduction/ Background 3% Contain a concise summary of the experiment that is carried out. Includes the statement of purpose, an introduction into technique used and a brief overview of the instrumentation. Material& Methodology 3% Contains all relevant experimental procedures, materials and instrument parameters used in the analysis or during the experiment. Results& Discussion 5% -Show all the results from the experiment by using graph, diagram, table, etc. All the data must be at appropriate units. The calculation should shows in systematic basis. Show only one example calculation for repeat data trials. Include statistical analysis if any. All results must be
expressed to correct significant figures and in correct units. -Explanation of the figures or graph or data should followed by supporting reference or relevant/logical analysis. Conclusion 2% Conclusion should reflect an understanding of the chemical theory involved and achievement of the experiment objective. Limitation of the experiment 2% It may include the limitation of the technique or methodology of the experiment based on literature study. Includes also any error that encounter during the experiment is carried out. Suggest for improvement to avoid error. Reference 3% A minimum of 3 references should be cited in the experiment report. Format 2% Front page, table of content, reference writing style, graph, figure, table, etc.
All the laboratory rules already learned will be applicable all the time and the students are required to comply with all the rules when there are in the lab.
1. Wear closed shoes, lab coat and eye protection (goggles) at all the time while in the laboratory. 2. DO NOT wear bulky clothes or loose sleeves and long pants. Wear suitable attire for lab work. Those with long hair do tie it before entering the lab. (lecturer/instructor preserve the right to not allow student who not follow this rule from enter the lab) 3. Switch off your hand phones. 4. Always be punctual. Students who come later than 15 minutes will not
allowed to perform the experiment. 5. Eating and drinking in the lab are strictly prohibited in the lab. 6. Students must have a towel (for cleaning purposes), a logbook and their lab manual during the lab session. 7. Clean your bench and return all the apparatus to their respective places before you leave the lab. 8. Read the lab manual and understand the lab before you going to the lab. 9. Use only the amount of the reagents required. Avoid wastage. 10. Dispose of excess reagents as instructed, never return excess reagents into the bottle. 11. Make sure you know where the following safety devices are: eyewash station, emergency shower, fire extinguisher, fire alarm station. 12. Clean up the broken glass and report to the lab instructor or lecturer immediately.
13. Always follow the instruction of the lab instructor or lecturer before start the lab. 14. Do not casually dispose chemicals into the sink. Some chemicals may washed down the sink, while others may require a different method of disposal. If a chemical can go in the sink, be sure to wash it away rather than risk an unexpected reaction between chemical ‘leftovers’ later.
EXPERIMENT 1: ISENTROPIC EXPANSION PROCESS
OBJECTIVES 1. To demonstrate the isentropic expansion process.
PROCEDURES 1. Perform the general start up procedures as stated in appendix A. Make sure all valves are fully closed. 2. Connect the hose from compressive pump to pressurized chamber. 3. Switch on the compressive pump and allow the pressure inside chamber to increase up to about 160kPa. Then, switch off the pump and remove the hose from the chamber. 4. Monitor the pressure reading inside the chamber until it stabilizes. Record the pressure reading PT 1 and temperature TT 1. 5. Then, slightly open valve V 01 and allow the air flow out slowly until it reaches atmospheric pressure. 6. Record the pressure reading and temperature reading after the expansion process. 7. Discuss the isentropic expansion process.
EXPERIMENT 2: BRIEF DEPRESSURIZATION
OBJECTIVES 1. To study the response of the pressurized vessel following a brief depressurization
PROCEDURES 1. Perform the general start up procedures as stated in appendix A. Make sure all valves are fully closed. 2. Connect the hose from compressive pump to pressurized chamber. 3. Switch on the compressive pump and allow the pressure inside chamber to increase up to about 160kPa. Then, switch off the pump and remove the hose from the chamber. 4. Monitor the pressure reading inside the chamber until it stabilizes. Record the pressure reading PT 1. 5. Fully open valve V 01 and bring it back to closed position after few seconds. Monitor and record the pressure reading PT 1 until it
becomes stable. 6. Display the pressure reading on a graph and discuss about it.
EXPERIMENT 3: THE FUNDAMENTAL PRESSURE-TEMPERATURE RELATIONSHIP OF SATURATED STEAM IN EQUILIBRIUM
OBJECTIVES 1. To demonstrate the relationship between the pressure and temperature of saturated steam in equilibrium. 2. To demonstrate the vapour pressure curve.
PROCEDURES 1. Perform the general start up procedures as stated in appendix B. 2. If the boiler is initially filled with water, open the valves at the level side tube to check the water level. Pour in additional distilled water if necessary. Then, close the valves. 3. Set the temperature controller to 185.0 °C which is slightly above the expected boiling point of the water at 10.0 bar (abs). 4. Open the valve at feed port and turn on the heater.
Important: Always make sure that the valves at the level sight tube are closed before turning on the heater as the sight tube is not designed to withstand high pressure and temperature.
Observe the steam temperature rise as the water boils. Allow steam to come out from the valve for about 30 seconds, and then close the valve. This step is important to remove air from the boiler as the accuracy of the experimental results will be significantly affected when air is present. 7. Record the steam temperature and pressure when the boiler is heated until the steam pressure reaches 10.0 bar (abs).
Warning: Never open the valve when the boiler is heated as pressurized steam can cause severe injury.
Then, turn off the heater and the steam temperature and pressure will begin to drop. Allow the boiler cool down to room temperature.
9. Record the steam temperatures at different pressure readings when the boiler is heated and cooled.
ASSIGNMENTS 1. Complete experiment data sheet. 2. Plot the graph of temperature, T against absolute pressure, P. 3. Measure/calculate the slope of the graph using certain points. Note: Tv fg dT h fg dP SAT Tv dT Plot versus P and fg versus P on a same graph. hfg dP SAT
Pressure, P (bar) Gauge Absolute Increase (0C)
Temperature, T (°C) Decrease (0C) Average Tavc (0C) Average Tavc (K)
Measured Slope, dT/dP
Calculated Slope, Tvg/hfg
DISCUSSION 1. Why is it necessary to remove air from the boiler at the beginning of the experiment? 2. Compare the graph plotted from experiment data to that of the calculated data. 3. 4. Discuss any discrepancy and sources of error of the experiment. Discuss the liquid and vapor behavior observed through the experiment and list some examples of its industrial applications.
EXPERIMENT 4: DETERMINATION OF RATIO OF VOLUME
OBJECTIVES 1. To determine the ratio of volume and compares it to the theoretical value.
PROCEDURES 1. Perform the general start up procedures as stated in appendix A. Make sure all valves are fully closed. 2. Connect the hose from compressive pump to pressurized chamber. 3. Switch on the compressive pump and allow the pressure inside chamber to increase up to about 160kPa. Then, switch off the pump and remove the hose from the chamber. 4. Monitor the pressure reading inside the chamber until it stabilizes. Record the pressure reading for both chambers before expansion. 5. Open valve V 02 and allow the pressurized air flows into the atmospheric chamber slowly. 6. 7. Record the pressure reading for both chambers after expansion. The experimental procedures can be repeated for the following conditions: a) From atmospheric chamber to vacuum chamber b) From pressurized chamber to vacuum chamber 8. Calculate the ratio of volume and compares it with the theoretical value.
EXPERIMENT 5: DETERMINATION OF RATIO OF HEAT CAPACITY
OBJECTIVES 1. To determine the ratio of heat capacity and compares it to the theoretical value.
PROCEDURES 1. Perform the general start up procedures as stated in appendix A. Make sure all valves are fully closed. 2. Connect the hose from compressive pump to pressurized chamber. 3. Switch on the compressive pump and allow the pressure inside chamber to increase up to about 150kPa. Then, switch off the pump and remove the hose from the chamber. 4. Monitor the pressure reading inside the chamber until it stabilizes. Record the pressure reading PT 1 and temperature TT 1. 5. Fully open valve V 01 and bring it back to closed position after few seconds. Monitor and record the pressure reading PT 1 and temperature TT 1 until it becomes stable. 6. Determine the ratio of heat capacity and compare it with theoretical value.
EXPERIMENT 6: DEMONSTRATION OF THERMODYNAMIC CYCLES
OBJECTIVES 1. To demonstrate an actual thermodynamic cycle (heat engine or refrigerator or heat pump) based on any equipment/machine available in UCSI. 2. To compare demonstrated thermodynamic cycle with theoretical cycle.
APPENDIX A : PERFECT GAS EXPANSION UNIT
General Start-up Procedures
1. Connect the equipment to single phase power supply and then switch on the unit. 2. Fully open all valves and check the pressure reading on the panel. This is to make sure that the chambers are under atmospheric pressure. 3. Then, close all the valves. 4. Connect the pipe from compressive port of the pump to pressurized chamber or connect the pipe from vacuum port of the pump to vacuum chamber. 5. Now, the unit is ready for use.
General Shut-down Procedures
1. Switch off the pump and remove both pipes from the chambers. 2. Fully open the valves to release the air inside the chambers. 3. Switch off the main switch and power supply.
APPENDIX B : MARCET BOILER
General Start-up Procedures
1. Perform a quick inspection to ensure that the unit is in proper operating condition. 2. Connect the unit to the nearest power supply. 3. Open the valves at the feed port and the level sight tube. 4. Fill the boiler with distilled water through the feed port and make sure that the water level is at about the half of the boiler’s height. Then, close the valves at the level sight tube. 5. Turn on the power supply switch. 6. Now you are ready to carry on with the experiment.
General Shut-down Procedures
1. Switch off the heater and allow the boiler temperature to drop. Note: Do not open the valve at the water inlet port as it is highly pressurized at high temperature. 2. Switch off the main switch and the main power supply. 3. Retain the water next use.