Download Worksheet- Gas LAW

High School
Classwork-12-Q-3
Subject-Chemistry
Name:
Grade:10
Date:
Teacher’s Name: Enas Parkar/Ali Zia
Marks:
Module 12 : Gas Laws
Gas laws
Gas laws are mathematical relationships that relate volume of a gas with
different external conditions like pressure, temperature etc.
1. Boyle’s law
“The volume of a fixed amount of gas held at a constant temperature varies
inversely with the pressure”.
1
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𝑃
And it can also be stated as:
P1V1 = P2V2 where P = pressure and V = volume
Boyle’s law relates volume and external pressure on gas graphically as follows:
2. Charle’s law
Charles’s law states that the volume of a given amount of gas is directly
proportional to its Kelvin temperature at constant pressure.
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Mathematically Charle’s law can be stated as:
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And:
Graphically Charle’s law can be represented as:
The gas volume does not essentially become zero at 0oC, instead by reducing the
temperature volume becomes nearly equal to zero at -273oC.
A temperature at which volume of gas essentially becomes zero is called absolute
zero, its value is -273oC or 0K(zero kelvin).
3. Avogadro’s principle
“States that equal volumes of gases at the same temperature and
pressure contain equal numbers of particles”.
• The molar volume of a gas is the volume 1 mol occupies at 0.00°C and 1.00
atm of pressure.
• 0.00°C and 1.00 atm are called standard temperature and pressure (STP).
•
At STP, 1 mol of gas occupies 22.4 L.
4. The Ideal Gas Law
The ideal gas law describes the physical behavior of an ideal gas in terms of
the pressure, volume, temperature, and number of moles of gas present.
PV = nRT
 The ideal gas constant is represented by R and is 0.0821 L•atm/mol•K
It combines all the laws together to give a general equation for the ideal gases.
• For a given amount of gas, the product of pressure and volume, divided by
the Kelvin temperature, is a constant.
Q.1. Choose the correct answer.
1. Which gas law describes the relationship between the volume and pressure of
a gas at constant temperature?
A) Boyle's Law
B) Charles's Law
C) Avogadro's Principle
D) Ideal Gas Law
2. What is the mathematical expression for Boyle's Law?
A) V 𝖺 T
B) V 𝖺 P
C) V 𝖺 1/T
D) V 𝖺 1/P
3. At what temperature does the volume of a gas essentially become zero
according to Charles's Law?
A) 0°C
B) -273°C
C) 100°C
D) -100°C
4. What is the molar volume of a gas at standard temperature and pressure
(STP)?
A) 1 L
B) 22.4 L
C) 0.0821 L•atm/mol•K
D) 1 atm
5. Which of the following gas law relates volume of gas with its number of
particles?
A) Boyle's Law
B) Charles's Law
C) Avogadro's Principle
D) Ideal Gas Law
Q.2. Label the following graphical representation as either Charle’s
law or Boyle’s law.
Charles Law
Boyle’s law
Q.3. Mark the following statements as either true or false and correct
the false statements.
1. The volume of a gas essentially becomes zero at 0°C according to Charles's
Law.
TRUE
2. At standard temperature and pressure (STP), 1 mol of gas occupies 22.4 L.
TRUE
3. The same volumes of different gases contain different number of particles.
TRUE
4. STP refers to 100 atm pressure and 50 °C of temperature.
False (STP refers to 1 atm pressure and 0°C or 273 K temperature.)
5. In Boyle’s law external pressure and temperature for the gas are taken as
constants.
TRUE
The End