GASEOUS STATE - Class 11 FULL CHAPTER 5 | Basic to JEE Advanced Level | Chemistry by Pahul sir

Vedantu JEE・2 minutes read

The text covers various topics related to the behavior of gases, such as the Ideal Gas Law, Dalton's Law of Partial Pressures, and diffusion rates. It also delves into the modifications made by Johannes Diderik van der Waals to the ideal gas equation to account for intermolecular interactions and the Wonderwall Equation of State for non-ideal gases.

Insights

The Gaseous State chapter, though removed from the CBSE syllabus, remains relevant for Thermodynamics, particularly for JEE exams.
Understanding concepts like the Ideal Gas Equation (Pavi = nRT) is crucial for solving questions related to ideal gas behavior.
Pressure, volume, and temperature play integral roles in gas calculations, with the Universal Gas Constant (R) being a key component in gas equations.
Dalton's Law of Partial Pressures simplifies the determination of total pressure in gas mixtures by considering the individual pressures of each gas component.
Diffusion and effusion are natural phenomena in gases, affected by factors like pressure, molar mass, and temperature, as per Graham's Law of Diffusion.
The Maxwell-Boltzmann distribution model explains the distribution of velocities of gas particles, illustrating how temperature affects the spread of energy among particles in a system.

Get key ideas from YouTube videos. It’s free

Recent questions

What is the ideal gas equation?
PV = nRT
What is Dalton's Law of partial pressures?
Total pressure is sum of individual gas pressures
What is the Maxwell-Boltzmann distribution?
Statistical model showing gas particle velocities
What is the rate of diffusion according to Graham's Law?
Rate proportional to pressure divided by square root of molar weight
What is the significance of the Wonderwall Equation of State?
Essential for understanding non-ideal gases and intermolecular forces

Related videos

Summary

00:00

"Essential Gas Concepts for JEE Exams"

Chapter of Gaseous State removed from CBSE syllabus but still relevant for Thermodynamics
Questions on Gaseous State likely in JEE exams
Questions on thermodynamics, equilibrium, kinetics, and applications in JEE exams
Ideal gas concept explained with molecules far apart
Ideal gas equation Pavi = nRT significant for questions
Pressure defined as force on gas container walls
Volume occupied by gas in container crucial for calculations
Number of moles of gas determined by weight and molar weight
Temperature in Kelvin essential for gas calculations
Universal gas constant R crucial for gas equations

17:19

"Gas Laws: Understanding Ideal Gas Behavior"

The Yamuna Expressway runs from Noida to Agra and Lucknow to Lucknow on cemented roads, causing vehicles to generate excess heat.
Excessive heat between car tires and cemented roads can lead to tire bursts on highways.
Tire pressure increases with temperature, and if not managed properly, tires can burst.
The volume of gas in tires can cause bursts if not regulated, as gas will escape if pressure increases.
The laws of fixing temperature, pressure, and volume are integral to understanding ideal gas behavior.
Avogadro's Law states that volume is proportional to the number of moles.
Equal volumes of gases at the same temperature and pressure contain the same number of molecules.
The ideal gas constant, R, varies based on the units of pressure and volume used in calculations.
The ideal gas equation, PV = nRT, is a fundamental concept in understanding gas behavior.
Real gases may not always follow the ideal gas laws due to complexities in their behavior.

34:59

SI Units in Chemistry: Essential Concepts Explained

SI units are crucial in chemistry, with Pascal being the correct unit for pressure and Cubic Meters for volume.
The SI unit of volume is not liter, but Cubic Meters, as per NCRT.
Pressure is not measured in ATM, but in Pascal.
Volume is derived from fundamental units of meters, with Cubic Meters being the result.
Energy or work done is measured in the unit obtained by multiplying pressure and volume.
Joule is the unit of energy, calculated as force multiplied by distance.
The Avogadro number is essential in chemistry, representing the number of molecules.
Boltzmann Constant is crucial in calculating the ideal gas constant, R.
The ideal gas equation can be manipulated using variations like Boyle's Law.
In practical applications, understanding units like Torr and millimeters of mercury is vital for pressure calculations.

54:46

Dalton's Law: Total Pressure Calculation in Gases

Dalton's Law of partial pressures states that the total pressure of a gas mixture is the sum of the individual pressures of each gas component.
The concept is illustrated using two gases, X and Y, where the total pressure on the container is the sum of the pressures exerted by each gas individually.
The pressure due to each gas component is termed as the partial pressure, with X having its own partial pressure and Y having its own as well.
Dalton's Law emphasizes that the total pressure is the combined effect of the individual pressures of each gas present in the mixture.
Understanding Dalton's Law aids in calculating the total pressure of a gas mixture by considering the partial pressures of each gas component.
The law simplifies the determination of total pressure by summing up the partial pressures of all gases in the mixture.
By applying Dalton's Law, one can accurately predict the total pressure exerted by a gas mixture based on the individual pressures of its components.
The law's principle is crucial in comprehending the behavior of gas mixtures and how their combined pressures are determined.
Utilizing Dalton's Law allows for precise calculations of total pressure in gas mixtures, enhancing the understanding of gas behavior in various scenarios.
Mastering the application of Dalton's Law is essential for accurately analyzing and predicting the total pressure of gas mixtures in scientific and practical contexts.

01:13:16

Gas Behavior and Interactions: A Summary

Dalton's Law of Partial Pressure explains that gases do not interact with each other, maintaining their individual behaviors.
In real gases, intermolecular forces can cause gases to attract or repel each other, affecting pressure.
The volume occupied by gases in a container is determined by the total volume of the container.
The equation for total pressure in a container with two gas components involves the total moles of each gas.
Mole fraction is calculated by dividing the number of moles of a gas by the total moles in the container.
Dalton's Law mathematically relates partial pressure to mole fraction, indicating the pressure contribution of each gas.
The total pressure exerted by a gas mixture can be calculated using the ideal gas equation.
Diffusion is the natural tendency of gases to intermix due to Brownian motion, causing random zigzag movements.
Brownian motion results from gas molecules colliding and moving randomly, leading to the spread of gases in a container.
The process of diffusion is exemplified by the spreading of perfume molecules in the air, showcasing the intermixing of gas molecules.

01:32:49

Gas Diffusion and Graham's Law Explained

At the fair, people roam randomly, similar to gases mixing when two are combined.
Gases diffuse and mix well when combined, like air around us.
Perfume scent spreads slower in winter due to lower temperatures and faster in summer due to higher temperatures.
The ideal gas law states that the number of molecules in two different containers will be the same if the gases are ideal.
Real gases may have slight differences in behavior compared to ideal gases.
Effusion occurs when gas escapes through a small hole due to pressure differences.
Diffusion rate can be measured by the number of moles escaping over time or the change in volume over time.
The rate of diffusion can be measured by the change in pressure over time if pressure is constant.
Temperature differences do not significantly affect diffusion rates.
Graham's Law of Diffusion states that lighter gases diffuse faster than heavier ones.

01:49:37

Gas Diffusion Rates and Pressure Relationships

Rate of Diffusion (R Diff) is proportional to the pressure of the gas divided by the square root of the molar weight of the gas.
Graham's Law of Diffusion states that the rate of diffusion of any gas is proportional to the pressure of the gas divided by the square root of the mass of the gas.
The rate of diffusion of oxygen (O2) dropped from 2000 torr to 1500 torr in 55 minutes.
When the same vessel was filled with another gas, the pressure dropped from 2000 torr to 1500 torr in 85 minutes.
The rate of diffusion of O2 is proportional to the pressure divided by the square root of the molar mass of O2 (32 grams).
The rate of diffusion for the other gas is also calculated similarly, with the pressure drop from 2000 torr to 1500 torr in 85 minutes.
The rate of diffusion of O2 is proportional to the pressure divided by the square root of the molar mass of O2 (32 grams).
The rate of diffusion for the gas is proportional to the pressure divided by the square root of the molar mass.
The rate of diffusion of HCl traveled 60 cm in a certain time, while NH3 traveled 40 cm in the same time.
By combining the equations for HCl and NH3 diffusion rates, the pressure is calculated to be approximately 255.

02:10:46

Understanding Ideal Gas Behavior and Properties

Kinetic Theory of Gases explains the behavior of gases based on the movement of their particles.
The Ideal Gas Equation is used to describe the behavior of ideal gases.
Ideal gases follow the Ideal Gas Equation accurately.
Different types of ideal gases exist, such as potholes.
Nature follows specific rules and characteristics when it comes to gases.
The derivation of the Kinetic Theory of Gases can be time-consuming but enjoyable if understood carefully.
The Wonderwall equation and additional concepts follow the Ideal Gas Equation.
The class duration is two hours and 12 minutes, with a break scheduled after two hours and 10 minutes.
Ideal gases have specific properties, including negligible volume for individual gas molecules and continuous random motion without intermolecular forces.
Collisions between gas molecules and container walls are elastic, with no energy loss during collisions.

02:42:38

Understanding Elastic Collisions and Force Equations

Change in velocity is simple to understand, considering the elastic collision with no energy loss.
Momentum is conserved in the collision, leading to a change in velocity.
Time is defined as the change in velocity when force is applied.
The equation for force is derived as mass times velocity squared divided by length.
The force exerted by all gas particles on the wall is calculated by summing the individual forces.
The total force is simplified by taking out common factors and summing the squares of velocities.
The average squared velocity is calculated by summing the squares of velocities and dividing by the total number of particles.
Pressure is determined by mass, number of particles, and the average squared velocity.
The total velocity of a particle is the sum of its components in different axes.
The average total velocity is calculated by summing the squared velocities of all components and dividing by the total number of molecules.

03:02:14

"Gas molecules in motion: a comprehensive guide"

Beans and roots are discussed in relation to a boat.
The concept of gases and molecules in a container is explained.
The randomness of Brownian motion and particle movement is detailed.
The system's randomness and behavior in different axes are highlighted.
The concept of total mean square velocity is introduced.
The relationship between velocity and mean square velocity is discussed.
The average kinetic energy of a molecule is associated with pressure and volume.
The total energy of an ideal gas system is explained.
The derivation of the total energy equation is outlined.
The Root Mean Square Velocity (RMS) concept is defined and simplified.

03:23:49

"RMS Velocity and Maxwell-Boltzmann Distribution Summary"

The main results from the Kinetic Theory of Gases are the RMS velocity, the velocity equal to √3 times the square root of the molar mass of the gas, and the RMS velocity formula.
To remember these results, it is suggested to revise the class notes and rewrite them for better understanding.
To calculate the RMS velocity and average kinetic energy of an O2 molecule at 18 degrees Celsius, first calculate the RMS using the formula √3 * R.
Ensure all calculations are done in SI units, with the temperature converted to Kelvin and the molar mass of O2 considered as 32 grams per mole.
The RMS velocity is approximately 476 m/s, calculated using the formula 8.314 * 291 / 32.
The Maxwell-Boltzmann distribution is a statistical model representing the distribution of velocities of gas particles.
The distribution shows that particles with lower velocities are more numerous than those with higher velocities, forming a bell curve.
Increasing the temperature of the system results in a wider spread of energy among the particles, with more particles having higher velocities.
The spread of energy in the system increases with higher temperatures, leading to a broader distribution of velocities.
The Maxwell-Boltzmann distribution graph shifts upwards and widens as the temperature of the system increases, indicating a higher energy spread among the particles.

03:42:15

Gas Velocity Distribution and Intermolecular Forces

The text discusses the concept of velocity distribution in gases, focusing on Maxwell Boltzmann distribution.
It explains how the velocity of gas particles varies, with heavier gases having lower velocities and lighter gases having higher velocities.
The text mentions that the most probable velocity in gases is determined by the peak of the distribution curve.
It delves into the statistical distribution of velocities, highlighting the most probable speed and the root mean square speed.
The text emphasizes the importance of memorizing formulas related to velocity distribution in gases.
It transitions from discussing ideal gases to real gases, noting the differences in behavior due to intermolecular forces.
The text introduces the work of scientist Johannes Diderik van der Waals, who modified the ideal gas equation to account for intermolecular interactions.
It explains the pressure correction needed in the modified gas equation to consider intermolecular forces of attraction.
The text uses a metaphor of hitting a wall to illustrate the impact of intermolecular forces on gas particles' behavior.
It concludes by encouraging a deeper understanding of the concepts discussed and warns against relying on incorrect derivations found online.

04:01:48

Pressure Reduction and Volume Correction in Gases

When hitting a wall, the force applied may be less than ideal due to an opposing force pulling back.
The reduction in pressure is proportional to the number of particles attracting each other.
The reduction in pressure is proportional to the number of moles per unit volume.
The first constant, A, in the pressure correction equation is determined by the intermolecular forces of attraction.
The volume correction factor accounts for the extra volume needed for molecules to rotate and their own volume.
The volume correction involves giving four times the volume of a molecule to accommodate its space.
The ideal case involves gases not needing space to exist, while the real case requires volume for molecules to occupy.
The volume correction factor ensures molecules have enough space to prevent collisions and maintain pressure and temperature.
The volume correction involves giving four times the volume of a molecule to accommodate its space.
The ideal case involves gases not needing space to exist, while the real case requires volume for molecules to occupy.

04:19:53

Gas Volume Correction Constants and Wonderwall Equation

The volume of one molecule is four times the volume you get, known as the VLS Correction Constant of Volume.
Volume correction for n mole of particles of gas involves multiplying the total number of moles by the correction constant.
The VLS Correction Constant of Volume is crucial for balancing collision rates in gases with different sizes.
The equation for volume correction involves subtracting the ideal volume from the real volume and adding the correction constant.
The Wonderwall Equation of State is essential for understanding non-ideal gases and their intermolecular forces.
The Wonderwall constant A values for gases O2, A2, A3, and CH4 are 1.36, 1.39, 4.17, and 2.25 respectively, indicating their ease of liquefaction.
NH3 is easier to liquefy due to its polar nature and strong intermolecular forces.
Understanding the dipole moments and intermolecular forces of gases aids in determining their ease of liquefaction.
Calculating the Wonderwall constant A involves analyzing the Pavi vs. Na Bavi plot and determining the slope of the graph.

Try it yourself — It’s free.