Westminster Kingsway College: Gas Laws Investigation Unit 14 Report

This report presents an investigation into gas laws, specifically focusing on Boyle's Law. The investigation involves an experiment using a syringe to vary the volume of a fixed mass of air while monitoring the pressure, keeping temperature constant. The report details the experimental procedure, collected data, and analysis of the relationship between pressure and volume. Furthermore, the report includes calculations related to pressure, volume, and temperature changes, and discusses the factors affecting reaction rates, such as concentration, pressure, temperature, surface area, and catalysts. It also explains how these factors influence industrial processes, particularly in the Haber process for ammonia production. The report concludes by analyzing the effects of pressure and temperature on reaction rates and equilibrium, linking the findings to real-world industrial applications.

College: Westminster Kingsway College Department: YAL-E: Science and Maths
Course title: BTEC ND Certificate in Applied Science
Assessor name (s): S Ikpe
Assignment title: Gas Laws Investigation Unit title: Unit 14 – Energy Changes, Sources and
Applications
Date set: wb 21/10/2013 Date due: wb 11/11/2013
Task Brief / Scenario:
Your laboratory has asked you to carry out an investigation into one gas law and to relate the outcomes of your
investigation to industrial processes
Work copied from other sources (e.g. books, websites, other students etc) and presented as your own work will
not be accepted – see Student Code & Disciplinary Procedures
Grading criteria: Marks
P2
M2
D2
Carry out an investigation into one gas law, relating them to industrial processes
Calculate pressure, volume, and temperature changes for gases in given industrial processes
Explain gas pressure and how it affects industrial processes
Your assignment must be handed in by the deadline. Please sign the declaration below and attach it to your work.
Declaration
Name: ...................................................................
This is my own work. Any sources I have used have been acknowledged appropriately.
I understand that work copied from other sources (e.g. books, websites, other students etc) and presented as my
own work will not be accepted.
Signed ………………………………………………. Date ..........................................
I accept the grade I have been awarded and I am now submitting this piece of work with the grade achieved
Name: ...................................................................
Signed ………………………………………………. Date ..........................................
Page 1 of 8

FEEDBACK: Unit 14 – Gas Laws Investigation
Name: ____________________________________________________
Criteria Teacher Feedback If you have failed the assignment or just
fallen short of a grade boundary – then you
may be given a re-submission opportunity.
How to improve your grade
P2
M2
D2
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Page 2 of 8

P2
The three macroscopic properties of a fixed mass of gas are its
Pressure (P)
Volume (V), and
Temperature (T)
a.) By investigating the relationship of any of the two properties while keeping the third constant, you will be
investigating a specific gas law. State what these laws are in terms of P, V, and T and then combine them to arrive at
the ideal gas equation in terms of the number of moles of the gas, n, and the molar gas constant, R.
The Gas laws
Boyle's Law states that, for a constant temperature of a fixed mass of a gas, the pressure of a given gas is inversely
proportional to its volume. In equation form it is given as:
P ∝ 1
V ⇒ PV =constant
Or: P1 V 1=P2 V 2
Charles's Law states that, for a constant pressure of a fixed mass of a gas, the volume of a gas is directly
proportional to temperature in Kelvin: In equation form it is given as:
V ∝T ⇒ V
T =constant
Or
V 1
T 1
= V 2
T2
Gay-Lussac's Law states that, for a fixed volume of a fixed mass of a gas, pressure is directly proportional to
temperature: In equation form it is given as:
P ∝T ⇒ P
T =constant
Or
P1
T1
= P2
T 2
Avogadro's Law states that, for constant temperature and pressure of a fixed mass of a gas, equal volumes of all
ideal gases contain the same number of molecules.
⇒ V
n =constant
Or
n1
V 1
= n2
V 2
Combined gas law: The combined gas law is given when Charles' Law, Boyle's Law, and Gay-Lussac's Law are
combined together to give:
PV
T =Constant
Or
P1 V 1
T 1
= P2 V 2
T 2
Ideal gas law: When Avogadro's Law is considered in the combined gas law, all four state variables (P, V, T and n) is
combined into one equation. i.e.
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V ∝n∧V ∝ T
P V ∝ nT
P
PV
nT =constant
The "constant" used in the above gas laws becomes the Universal Gas Constant (R).
PV
nT =R
Or;
PV =n R T
b.) Carry out a practical investigation on one of the gas laws using the instructions provided. Report your investigation
using standard procedures. What relevance is the outcomes of your investigation to Industrial Processes?
Investigation of Boyle's Law:
It state that, for a constant temperature of a fixed mass of a gas, the pressure of a given gas is inversely
proportional to its volume. In equation form it is given as:
P ∝ 1
V
Here, use of a syringe to investigate the Boyle’s law. Here, the volume of a fixed mass of trapped air in a syringe is
varied while the pressure is monitored with a pressure sensor as shown in the figure below: The temperature is
kept constant (Room temperature)
The following is the value taken
Volume
(cm3)
Pressure
(Atm)
9.0 120
6.0 180
5.0 220
4.0 280
3.5 320
3.0 380
2.5 440
The following shows the relationship between pressure and volume of a fixed mass of a gas at constant
temperature.
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2 3 4 5 6 7 8 9 10
0
50
100
150
200
250
300
350
400
450
500
Pressure-Volume graph
Volume
Pressure
Page 5 of 8

M2
Question 1
a.) A fixed mass of gas has an initial volume V 0 and an initial pressure p0. It is first compressed at constant
temperature of 27 oC until its volume is reduced to 1
4 V 0
. State the pressure of the gas, in terms of p0, at the end of
this process
P1= p0V 1=V 0T 1=T 2=27 ℃=300 K P1 V 1
T 1
= P2 V 2
T 2
For a constant temperature:
P1 V 1=P2 V 2
P2= P1 V 1
V 2
= p0 V 0
1
4 V 0
=4 p0 ∴ the Presure is 4×p0
b.) The temperature of the gas is now increased until its volume returns to V 0. Throughout this process, the gas is
allowed to expand in such a way that its pressure remains constant. Calculate the final temperature, in oC, of the gas.
P1=P2=4 p0V 1= 1
4 V 0V 2=V 0T 1=3 00 K P1 V 1
T 1
= P2 V 2
T 2
For a constant pressure:
V 1
T 1
= V 2
T2
⟹ T2 =V 2 T1
V 1
= 300V 0
1
4 V 0
=300
1
4
=4 ×300 K =1200 K ¿ 727 ℃
c.) Illustrate these two changes on a graph of pressure against volume.
Describe the third change that is required to complete the ‘cycle’ of changes, i.e. to return the gas to its original
conditions.
The third condition is changing the pressure, reducing pressure to p0while keeping volume constant. i.e.
P1 V 1
T 1
= P2 V 2
T 2
For a constant volume:
P1
T1
= P2
T 2
P1=4 p0 ; P2= p0T 1=727 ℃=1200 K ⟹ T2 = P2 T1
P1
= p0 × 1200
4 p0
=1200
4 =300 K ¿ 27 ℃
Thus, the temperature reduces to its original value of 27 ℃
Question 2
The table given above contains corresponding readings of temperature and pressure recorded for a fixed mass of gas
at constant volume. Unfortunately, one of the temperature readings has been recorded incorrectly.
a.) Find out which one
Changing temperature from degrees to Kelvin
Page 6 of 8
Temperature/ oC 1 12 29 34 58 78
Pressure/ kPa 96 100 106 111 11
6
123
Temperature/K 27
4
285 30
2
307 33
1
351
Pressure/ kPa 96 100 10
6
111 11
6
123

Plotting the graph of pressure against temperature will give the value not incorrectly recorded
270 280 290 300 310 320 330 340 350 360
0
20
40
60
80
100
120
140
Pressure-Temperature Graph
Temperature (K)
Pressure
The one incorrectly recorded is 34
b.) Use all the other data to determine the correct value for this temperature. Show all your working.
From Gay-Lussac's Law:
P1
T1
=constant 96
274 =0.3503649635=0.35 100
285 =0.350877193=0.35 106
302 =0.3509933775=0.35
111
307 =0.3615635179=0.36 116
331 =0.3504531722=0.35 123
351 =0.3504373504=00.35
At temperature equal to 34oC, the constant value changes.
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D2
1. State the factors that can alter the rate of reaction between substances. Identify the effectiveness of these factors
to reactions involving substances in the three states of matter – solid, liquid and gas.
There are several factors that affect the rate of reaction, some are discussed below:
a) Concentration:
Reaction occurs when reactant constituent particles (such as ions, atoms or molecules) come into contact.
No reaction occurs when there is no contact of the particles. Furthermore, when reactant particles colliding
per given time is high, then the more often a reaction between them can occur. Therefore, when
concentration of the reactants increases, the rate of reaction increases. According to collision theory,
reducing the concentration of a reactants reduces the number of collisions between the reactants per time
and thus decreases the reaction rate. This factor affect the three (3) state of matter.
b) Pressure
The concentration of a given gas is a function of the pressure on the gas. When pressure of a gas is
increased, there is increase in concentration. Therefore increase in rate of reaction of gases.
c) Volume of the container.
Increasing volume of a container holding the gas, reduces the pressure inside that container. Therefore, the
concentration of the gas reduces, hence reduction in reaction rate of the gas
d) Temperature
Temperature affect all the three state of matter, under some exception of precipitation reactions which
involves ionic compounds in solutions, chemical reactions increases with increase in temperatures.
Increase in temperature increases the kinetic energy of the particles in a substance, thus increase the
collision rate resulting to higher reaction rate.
e) Surface area
The interaction surface area between the reactant, the higher the surface area the more collision of
particles. Thus hiher surface area the more the reaction
f) Catalyst.
A catalyst is a substance that increases the rate of reaction, but do not take part of reaction. In some
reaction are affected by introduction of a catalyst.
2. In the manufacture of ammonia by the Haber process, the rate of reaction between the hydrogen and the nitrogen
is increased by the use of very high pressures. Explain.
A higher pressure increases the percentage yield of ammonia. From the reaction below
N2 ( g )+ 3 H 2 ( g ) ⇌ 2 N H3 (g) ∆ H =−92 kJmo l−1
From the reaction equation, the right side has two molecules of gas. If the pressure is increased, the equilibrium
position moves to the right, thus more ammonia will be produced. From gas law, increase in pressure increases the
collision rate thus increase in reaction rate.
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