ResultExperiment 1: Boys Law ExperimentConditionTypes of ChamberPressure (kpa)Temperature (oC)

Before ExpansionVacuum57.023.4

Pressure150.724.1

After ExpansionVacuum118.126.3

Pressure118.622.6

Table: Pressure reading for both chambers before and after expansion

Experiment 2: Gay-Lussac Law ExperimentPressure (kPa)Trial 1Trial 2Trial 3

Temperature (oC)Temperature (oC)Temperature (oC)

PressurizedDepressurizedPressurizedDepressurizedPressurizedDepressurized

11524.424.524.125.724.125.6

12524.525.824.826.524.526.9

13524.726.525.027.125.027.6

14525.227.225.427.425.828.2

15526.127.526.227.526.728.4

16526.528.026.827.927.728.6

Pressure (kPa)Average reading temperature

Temperature (oC)

PressurizedDepressurized

11524.225.3

12524.626.4

13524.927.1

14525.527.6

15526.327.8

16527.028.2

Table : The pressure and the average temperature in pressurize and depressurize vessel

Graph 1: The graph of Pressure versus Pressurized Temperature.

Graph 2: The graph of Pressure versus Depressurized Temperature.The pressure is directly proportional to temperature. Hence, the Gay-Lussacs Law is verified.

Experiment 3: Isentropic Expansion ProcessConditionPressure, PT1 (kPa)Temperature, TT1 (oC)

Before Expansion160.026.6

After Expansion103.523.2

Table: The pressure and temperature reading in pressurized chamberExperiment 4: Stepwise DepressurizationPressure, PT1 (kPa)

Before ExpansionAfter Expansion

1st Trial2nd Trial3rd Trial 4th Trial

160121.8131.3126.5132.0

Graph 3: Response of pressurized vessel following stepwise depressurization. Experiment 5: Brief DepressurizationConditionPressure, PT1 (kPa)

Before Expansion156.0

After Expansion109.5

Graph 4: Responses of pressurization vessel following of brief depressurization

CALCULATIONSV1 (pressure vessel) = 0.02500 m3V2 (vacuum vessel) = 0.01237 m3Experiment 1: Boyles Law ExperimentIdeal gas equation, PV=RT. For Boyles law, temperature is constant at room temperatureHence, R= 8.314 L kPa K-1mol-1, T= 298.15 @ 25CFrom pressurized chamber to atmospheric chamber1. For Pressure vesselBefore expansion = 150.7 kPa,After Expansion = 118.6 kPa. Then V1 and V2 is calculatedV1= RT/P1= (8.314 L kPa K-1mol-1) (298.15 K) / (150.7 kPa)V1 = 16.45 LV2 = (8.314 L kPa K-1mol-1) (298.15 K) / (118.6 kPa)V2 = 20.90 LAccording to Boyles law: P1V1=P2V2(150.7 kPa)(16.45 L) = (118.6 kPa)(20.90 L)2479.015 kPa.L = 2478.740 kPa.LP1V1 P2V2 (proved)1. For Vacuum vesselBefore expansion = 57.0 kPa,After Expansion = 118.1 kPa. Then V1 and V2 is calculatedV1= RT/P1= (8.314 L kPa K-1mol-1) (298.15 K) / (57.0 kPa)V1 = 43.49 LV2 = (8.314 L kPa K-1mol-1) (298.15 K) / (118.1 kPa)V2 = 20.99 LAccording to Boyles law: P1V1=P2V2(57.0 kPa)(43.49 L) = (118.1 kPa)(20.99 L)2478.93 kPa.L = 2478.92 kPa.LP1V1 P2V2 (proved)Boyles Law,P1V1 = P2V2(150.7 0.025) + (57.0 0.01237) = (118.6 0.025) + (118.1 0.01237)3.7675 + 0.7051 = 2.9650 + 1.46094.4726 kPa.L = 4.4259 kPa.LThe difference is 0.0467Experiment 3: Isentropic Expansion Process

T2/T1 = (P2 / P1)(k-1 / k)(23.2) / (26.6) = [(103.5) / (160.0)](k-1 / k)0.8722 = (0.6469) (k-1 / k)ln 0.8722 = [(k-1)/ k] ln 0.6469-0.1367 = [(k-1)/k](-0.4356)0.3138 = [(k-1)/k]k = 1.4573The difference is (1.4573-1.4) x 100 = 5.73%Where actual k = 1.4theoretical k = 1.4573

DiscussionBoyles law stated that the gas pressure is inversely proportional to the volume of the container with constant temperature. The boyles law relationship is expressed as P1V1=P2V2 (Boyle's Law - pressure, 2012). The conducted experiment of the gas movement from pressurized chamber to atmospheric give the initial reading of pressure is 150.7 kPa and after the expansion is 118.6 kPa. While for the vacuum vessel, the initial reading is 57.0 kPa and the after expansion reading is 118.1 kPa. The calculated result shows that the PV value before and after the expansion are 4.4726 kPa.L and 4.4259 kPa.L respectively. The difference of both reading is only about 0.05 which then can be stated that the boyles law is verified.Gay-Lussacs Law stated that the pressure is directly proportional to the temperature (Gay-Lussacs Law, n.d.). In order to investigate this statement the experiment 2 was conducted and the data collected is tabulated. The graph then plotted by using the tabulated data which give a verification of the exact pattern as stated by gay-lussac law which is as the temperature increased, the pressure of the chamber increased. This is because of the heat energy of the system transfer its energy into the molecule of gas that increase the frequency of collision in that container which then exerted more pressure.Isentropic Expansion Process occur when the system is reversible and adiabatic which is no heat will be transferred in or out and no energy transformation occur. From the recorded data the k constant is determined to be 1.4573 and it is observed that both temperature and pressure of the gas before expansion were higher compared to the temperature after the expansion. The process was then said to be isentropic as the expanding gas does not exchange the heat with the surrounding throughout the process (Ahrens, 1967). It then further verified with the calculation that give the different of only 5.73% which prove the process is isentropic.Stepwise depressurization is a strategy to adopt an equal time-stepwise depressurization approach. This study help in yielding more reliable result for a reference in the production sector industries. The molecule in the chamber affected when the number of them decreasing slowly as they do not have to collide between them often. The plotted graph shows two different pattern which are the pressure increase with time and also decrease with time. This might be caused by the error of time setting in conducting the experiment as the opened valve need to instantly closed directly after it is fully opened. However, at certain time the data give a pattern that follows directly with the theory which is the pressure is decreased as the temperature decreased in the system. Brief depressurization is conducted in order to investigate the response of the pressurized vessel following a brief depressurization. The pressure reading is compared between before and after the valve is opened. The pressure reading before the valve opened was 156.0 kPa and after the valve opened for a few second, the valve is closed back and the pressure recorded is 109.5 kPa. The graph then plotted and the pattern shows a linearly decreased graph with the decreasing value of 46.5 kPa. This is due to the expansion that occur when the pressure of gas increased and the pressure will decreased as the gas free to flow.

ReferencesAhrens, M. C. (1967). Thermodynamic of the Adiabatic Expansion of a Mixture of Two Phases. American Journal of Physics, 1-5.BOYLE'S LAW - (PRESSURE). (2012). BASIC GAS LAWS, 1-4.Edmund Y. Ting, C. L. (2009). Systems and methods to slowly reduce the pressure in a pressure chamber over time . 1-2.GAY-LUSSACS LAW. (n.d.). THE GAS LAWS, 2.