used determine the relationship between pressure and temperature at constant volume of an ideal gas

1. Koya University
Faulty of Engineering
School of Chemical & Petroleum Engineering
Chemical Engineering department
EXPERIMENT NUMBER THREE
GAY LUSSAC LAW
Thermodynamics
GAY LUSSAC LAW
Instructor: Mr.Rebwar & Mr.Omer
Author Name: Aree Salah Tahir
Experiment Contacted on: 19/nov/2013
Report Submitted on: 26/nov /2013
Group:A

2. List of content:
Abstract ………………………………….….2
Objectives……………………………….…...3
Introduction …………………………………4
Background Theory …………………….5 & 6
Method …………………………………7 & 8
Calculation…………………………….9 & 10
Equipment and components used…………..11
Discussion …..…………………12 & 13 & 14
References …………………………………15

3. Abstract:
Gay-Lussac's 1801 experiments establishing the law of
volumes for gases are brilliantly simple, and he described
them with a level of detail that was new to physics
writing. But he did not present his actual measurements
or tell us how he analyzed them to conclude that between
0 to 100 °C, a volume of any gas will expand by about
37.5%. We review his experiments and conclude that he
measured initial and final volumes at slightly different
pressures. By using the gas laws and his apparatus
diagrams, we corrected his data so that they correspond
to constant pressure. His corrected results give
ΔV/V=36.6%, the currently accepted value for nearly
ideal gases. Aside from their intrinsic interest, our
analyses can provide students intriguing applications of
the gas laws and Pascal's law and motivate them to
consider Pascal's paradox. We also note the influence of
ballooning and of the French Revolution on GayLussac.{ 1 }
2

4. OBJECTIVES:
The aim of this experiment is to determine the
relationship between pressure and temperature
at constant volume of an ideal gas.{ 2 }
3

5. Introduction:
When you have a can of soda or beer, and you heat it too
much by leaving it in your car or out in the sunlight for too
long a period of time, you may find an unpleasant surprise
when you return to fetch it, as people have found
out here and here. The amount of liquid in the can hasn't
grown. Instead, the carbon dioxide inside has been agitated
thermally, thus increasing the pressure, and you then have
to deal with the messy results of container bursting due to
this increase in kinetic energy. Inconvenient incidences of
pressurized containers exploding when they are heated may
be explained by the Law of Gay-Lussac.
Gay-Lussac's Law is the third and final of the laws leading
up to the ideal gas law. The first is Boyle's Law, which
gives the relationship between volume and pressure, and
the second is Charles' Law, which gives the relationship
between volume and temperature. Gay-Lussac's Law has
also been referred to as Charles' Law, but they are not the
same.{3}
4

6. BACKGROUND THEORY:
Gay-Lussac law is also commonly known
as Charles’s law.
The law explains about the relationship between pressure
and temperature of gases. The law was established in the
early19th
century by Jacques Charles and Joseph Louis GayLussac who did a study on the effect of temperature on
the volume of a sample of gas subjected to constant
pressure (Atkins,2002). Charles did the original work,
which was then verified by Gay-Lussac (grc.nasa.gov).
However, in this lab practical, we are dealing with an
alternative version of Charles’s
law instead. The volume is kept constant in change for
pressure instead as the objective of the experiment is to
determine the relationship between pressure and
temperature of ideal gas. The expression is as shown:
p = constant x T (at constant volume)
This version of law also indicates that the pressure of gas
falls to zero as the temperature is reduced to zero
(Atkins, 2002).
Thus it can be seen that gas pressure and the temperature
are directly proportional tone another.
When the pressure increases, the temperature also
increases, and vice versa.
5

7. P ∝T
P = constant T
P/T = constant
P1/T1= P2/T2
P1T2= P2T1
The equations above apply in the gas of dealing with the
relationship between pressure and temperature of a gas
Mathematical/Graphical relationship between pressure
of a fixed mass of gas with temperature at a constant
volume is linear. The volume is constant. { 4 }
6

8. Method:
Heating:
1.switch on unit at master switch.
2.open air discharge valve on the lid of the heatable
cylinder and set the vessel to ambient pressure .
3.close air discharge valve again.
4.set the required final temperature on the heating
regulator using the arrow keys
5.start data acquisition program and make the
corresponding settings.
6.switch on heater and operate as long as necessary
until the final temperature is reached.
7.open graph of measured values and interpret.
8. leave the cylinder unchanged and continue
immediately with the cooling experiment .
7

9. Cooling
1.switch off heated
2.open air discharge valve on the lid of the heatable
cylinder and set the vessel to ambient pressure.
3.close air discharge valve again.
4. start data acquisition program and make the
corresponding settings.
5.leave the vessel to cool to ambient temperature .
6. open graph of measured values and interpret.
7.open air discharge valve on the lid of the cylinder and
set the vessel to ambient pressure .
8.switch off unit at master switch.
8

10. EQUIPMENT & COMPONENTS USED:
(1) Tank 1 for isothermal change of state,
(2) Digital displays,
(3) 5/2-way valve for switching between
compression and expansion,
(4) Heating controller,
(5) Digital display,
(6) Tank 2 for isochoric change of state
(7) Red switch to on and off the machine{5}
11

11. Discussion:
1/Heating:
12

12. Cooling:
There are many erorrs in the chart because of mistakes
in the machine and the heater.
13

13. 1/ What restrictions are there on the use of
Gay-Lussac's law of combining volumes?
It applies only to gases measured under the
same temperature and pressure.
2/ At the same temperature and pressure, what
is the relationship between the volume of a gas
and the number of molecules present?
The volume varies directly with the number of
molecules.
3/ What is Gay-Lussac's Law?
the density of an ideal gas at constant pressure
varies inversely with its temperature.
Formulated by Joseph Louis Gay-Lussac, this
means that for any given amount of ideal gas
held at a constant volume, the pressure is
proportional to the absolute temperature.
4/why it is double glass?
For safty because maybe the inner glass will
explode
5/why do we have too much erorrs?
Because of the machines' getting old and the
room temperatur
14

14. References:
1: http://scitation.aip.org/content/aapt/journal/ajp/79/1/10.1119/1.3485034
2: http://www.scribd.com/doc/177444955/The-Perfect-Gas-Expansion-Experiment-TH-11
3: http://www.brighthubengineering.com/hvac/26213-gay-lussacs-law/#imgn_0
4: http://www.scribd.com/doc/177444955/The-Perfect-Gas-Expansion-Experiment-TH-11
5:http://www.gunt.de/networks/gunt/sites/s1/templates/scripts/picDetail.php?actEntry=3438&lang=1&di
r=06010200&src=Zeichnung.jpg&color=FF6633&software=1
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