Examples of Gases

Edited By Team Careers360 | Updated on Jul 02, 2025 04:54 PM IST

Gas is a type of state of matter which has no shape, size, and volume compared to solid and liquid forms. Gas has a property that it takes the shape and volume of the container where it is present. For gaseous matter, the particles that are elements or compounds are arranged in such a way that the distance between two particles is very large. To find a particle in its gaseous form is difficult. Air is an example of a gas which contains different types of compounds. Air is present all around us and we cannot even think that it contains too many compounds of gases.

This Story also Contains

Properties of Gases
Examples of gases
Ideal Gas Versus Real Gas
Gas Name
Types of Gas
Applications of Gases

Air is a mixture of nitrogen, carbon dioxide, oxygen, hydrogen, carbon dioxide, water vapour, and small amounts of other compounds like argon, neon, krypton, etc. The main component of air is nitrogen that is, 78 % of our air is filled with nitrogen gas. And then comes the oxygen about 20.9%. All the other gases in 0.17 %. At higher regions of air triatomic oxygen is found that is ozone.

Figure showing the composition of air

Properties of Gases

Indefinite Shape and Volume - Gases take the shape and volume of their container.
Compressibility - Gases can be compressed due to the large spaces between particles.
Low Density - Gases have lower density compared to solids and liquids.
Diffusion and Effusion - Gases spread out and mix without external forces, and they can pass through small openings without collisions.
Pressure Exertion - Gas molecules exert pressure on the walls of their container due to their constant motion.

Also read -

NCERT Solutions for Class 11 Chemistry	NCERT solutions for Class 11 Chemistry Chapter 5 States of Matter
NCERT Solutions for Class 12 Chemistry	NCERT Exemplar Class 11 Chemistry Solutions Chapter 5 States of Matter
NCERT Solutions for All Subjects	NCERT notes Class 11 Chemistry Chapter 5 States of Matter

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Some of the very common examples of compounds that are present in their gaseous form are described below.

Air
Argon
Nitrogen
Carbon dioxide
Helium
Oxygen
Ozone
Water vapour

For a molecule to be in its gaseous form requires certain conditions. But many elements can be accessed in their gaseous form even at room temperature and at ordinary pressure. They are hydrogen, oxygen, nitrogen, chlorine, and fluorine. And they are present in their diatomic form. That is H₂, O₂, N₂, Cl₂, and F₂. Oxygen tends to form gas even in its triatomic former and it is the very important compound ozone that is O₃ protects us from severe ultraviolet radiation.

The noble gases as the name suggests that noble gases have the property of existing in gaseous form even at room temperature and it is present in its monoatomic form. That is He, Ne, Ar, Kr, Rn, etc. are all gases and given the name pure gases. Water is a compound that can exist in the vapour form that is the gaseous former only at a particular temperature and pressure. Water is a compound that is in liquid form at room temperature and ordinary pressure. The gaseous form of water at a particular temperature and pressure is called water vapour.

Ideal Gas Versus Real Gas

A gas that behaves based on the Kinetic molecular theory and according to the law of ideal gas is ideal. This means that the particles present in an ideal gas are not attracted to each other have no volume and their interaction is perfectly elastic. This fact is the only theoretical basis not any gas in the world is not ideal. But under certain conditions that is at ordinary temperatures and pressures, their behavior is sometimes close to the ideal gas behavior that is verified by the use of ideal gas law.

The behaviour of real gases deviates from ideality at low temperatures and high-pressure conditions. The reason behind this is that under high pressure the molecules of gases come close to each other and the behavior of gas is lost. Also at high pressure, a gas molecule can be compressed into its liquid form itself. So then what is the case of low-temperature, the particles present in the gases need the energy to vibrate and to interact. If the temperature is low the kinetic energy of the particle will be low and the nature of perfect elastic collision has been lost.

Related Topics,

Gas Name

Some of the gas name and their formula is given below.

Name	Formula
Carbon dioxide	CO₂
Oxygen	O₂
Nitrogen	N₂
Helium	He
Ozone	O₃
Fluorine	F₂

Types of Gas

Some of the elements can exist in their gaseous form at the standard temperature for ordinary temperature and pressure but certain other elements cannot exist in these circumstances but can exist by applying certain conditions on it. Some of the types of gases based on this are described below.

Elemental Gases

The type of gases that can exist in their gaseous form even at the standard temperature or ordinary temperature and pressure are elemental gases. If the pressure or temperature is raised or lowered it can exist in a different form that is liquid form and its solid form. Examples of these elemental gases are hydrogen, oxygen, helium, fluorine, chlorine, etc.

Pure Gases

The gas that is made up of their atom that is present in a monoatomic former are called up you are gases. Examples of these included all the noble gases such as neon, helium, argon, krypton, etc. The picture of gases is shown below.

Picture of gases

Mixed Gases

The gases that contain more than one element or more than one atom are mixed gases that are it is a mixture of different gases. Carbon dioxide is one of the very important examples as it is a mixture of carbon and oxygen. Acetylene C₂H₂, butane C₄H₁₀, ethane C₂H₆, methane CH₃, Sulphur hexafluoride SF₆, etc. are gas mixture examples.

Toxic Gases

The gases that are toxic which means can cause harm to people when they breathe. Ozone is a toxic gas. Carbon monoxide, hydrogen bromide, hydrogen chloride, ozone, nitrogen dioxide, etc. are some of the poison gas names.

Applications of Gases

Gases are widely used in various industries and daily life:

Oxygen (O₂) - Essential for respiration and medical applications.
Nitrogen (N₂) - Used in food preservation and industrial processes.
Helium (He) - Used in balloons, MRI machines, and deep-sea diving.
Hydrogen (H₂) - Used in fuel cells and industrial synthesis.
Carbon Dioxide (CO₂) - Used in carbonated beverages, fire extinguishers, and plant growth

Frequently Asked Questions (FAQs)

1. What is the difference between an ideal gas and a real gas?

An ideal gas follows the ideal gas law (PV=nRT) under all conditions, assuming no intermolecular forces and negligible molecular volume. In contrast, real gases deviate from this behaviour at low temperatures and high pressures due to intermolecular attractions and the finite volume of molecules.

2. What is the difference between an ideal gas and a real gas?

An ideal gas is a theoretical concept assuming gas particles have no volume and no attractive forces between them. Real gases have particle volume and intermolecular forces, deviating from ideal behavior, especially at high pressures and low temperatures.

3. Why do gases expand to fill their container?

Gases have no fixed shape or volume because their molecules are in constant random motion and spread out to occupy any available space. This behaviour is due to the weak intermolecular forces and high kinetic energy of gas particles.

4. How many types of gas?

There are mainly four types of gas they are; elemental, mixed, pure, and toxic gas.

5. Why is carbon monoxide (CO) dangerous?

Carbon monoxide is a colourless, odourless gas that binds to haemoglobin in the blood more effectively than oxygen. This reduces oxygen transport in the body, leading to poisoning, which can be fatal in high concentrations.

6. How does temperature affect gas behaviour?

According to Charles’s Law, gas volume increases with temperature when pressure is constant. This is because higher temperatures increase the kinetic energy of gas molecules, causing them to move faster and spread out.

7. Why do balloons filled with helium float?

Helium-filled balloons float because helium is less dense than air. The upward buoyant force exerted by the surrounding air is greater than the downward gravitational force on the helium and balloon material, resulting in a net upward force.

8. How does gas pressure change with altitude in the atmosphere?

Gas pressure decreases with increasing altitude in the atmosphere. This is because there are fewer gas particles above as you go higher, resulting in less weight of air pressing down. The relationship between pressure and altitude is approximately exponential.

9. How do gases contribute to the ozone layer, and why is it important?

The ozone layer in the stratosphere is composed of ozone gas (O₃) formed by the interaction of oxygen molecules with ultraviolet radiation. This layer is crucial because it absorbs harmful UV-B radiation from the sun, protecting life on Earth from its damaging effects.

10. What is the role of gases in the water cycle?

Gases play a crucial role in the water cycle, primarily through evaporation and condensation. Water vapor, a gas, evaporates from water bodies and transpires from plants. It then condenses in the atmosphere to form clouds and eventually returns to Earth as precipitation.

11. What is the role of gases in the formation of volcanic eruptions?

Gases play a crucial role in volcanic eruptions. Dissolved gases in magma, such as water vapor, carbon dioxide, and sulfur dioxide, expand as pressure decreases during magma ascent. This expansion creates bubbles that increase magma volume and pressure, driving explosive eruptions.

12. How do gases contribute to the formation of auroras?

Auroras (Northern and Southern Lights) occur when charged particles from the sun collide with gas particles in Earth's upper atmosphere. Different gases emit different colors of light when excited: oxygen produces green and red light, while nitrogen produces blue and purple hues.

13. How do gases contribute to the formation of acid rain?

Gases like sulfur dioxide (SO₂) and nitrogen oxides (NOx) react with water, oxygen, and other chemicals in the atmosphere to form acidic compounds. These compounds then fall to Earth as acid rain, which can harm ecosystems, corrode buildings, and affect water quality.

14. What is the role of gases in the carbon cycle?

Gases, particularly carbon dioxide (CO₂), play a vital role in the carbon cycle. CO₂ is exchanged between the atmosphere, oceans, and terrestrial ecosystems through processes like photosynthesis, respiration, and decomposition. Understanding this cycle is crucial for climate science and environmental studies.

15. Why are some gases flammable while others are not?

Flammable gases, like methane or hydrogen, can readily react with oxygen in the presence of an ignition source to produce heat and light. Non-flammable gases, like nitrogen or carbon dioxide, do not undergo this type of rapid oxidation reaction under normal conditions.

16. How do gases contribute to the formation of planets and stars?

Gases play a crucial role in the formation of planets and stars. In space, large clouds of gas (primarily hydrogen and helium) collapse under gravity, forming dense regions that eventually become stars. Leftover gas and dust can coalesce to form planets, with some gases becoming part of planetary atmospheres.

17. How does temperature affect the behavior of gases?

Increasing temperature increases the kinetic energy of gas particles, causing them to move faster and collide more frequently with container walls. This leads to higher pressure if volume is constant, or expansion if pressure is constant.

18. Why do gases exert pressure on their containers?

Gases exert pressure because their particles are in constant, rapid motion, colliding with the container walls. These collisions transfer momentum to the walls, resulting in a force per unit area, which we perceive as pressure.

19. How does Avogadro's law relate to gases?

Avogadro's law states that equal volumes of gases at the same temperature and pressure contain the same number of particles. This means that the volume of a gas is directly proportional to the number of moles of gas present, assuming constant temperature and pressure.

20. What defines a gas in chemistry?

A gas is a state of matter characterized by particles with high kinetic energy, no fixed shape or volume, and the ability to expand to fill any container. Gas particles move rapidly and randomly, with large spaces between them compared to liquids and solids.

21. What is the most abundant gas in Earth's atmosphere?

Nitrogen (N₂) is the most abundant gas in Earth's atmosphere, making up about 78% of the air we breathe. Oxygen (O₂) is the second most abundant at about 21%.

22. How do gases contribute to the greenhouse effect?

Greenhouse gases, such as carbon dioxide (CO₂), methane (CH₄), and water vapor (H₂O), absorb and emit infrared radiation. They trap heat in the atmosphere, leading to the warming of Earth's surface and lower atmosphere.

23. What is the difference between diffusion and effusion in gases?

Diffusion is the movement of gas particles from an area of high concentration to an area of low concentration. Effusion is the process of gas particles escaping through a tiny hole in a container. Effusion rate depends on the mass of gas particles, while diffusion rate depends on concentration gradient and particle size.

24. Why are some elements gases at room temperature while others are solids or liquids?

The state of matter at room temperature depends on the strength of intermolecular forces. Elements with weak intermolecular forces (like noble gases) are gases, while those with stronger forces (like metals) are solids or liquids at room temperature.

25. What is the difference between condensation and liquefaction of gases?

Condensation is the process of a gas changing to a liquid when cooled to its dew point. Liquefaction involves compressing a gas at a temperature below its critical temperature to convert it to a liquid. Both processes result in the gas becoming a liquid, but the methods differ.

26. How do gases affect sound transmission?

Gases serve as a medium for sound transmission. Sound waves propagate through gases by causing compressions and rarefactions of gas particles. The speed of sound in a gas depends on factors like temperature, pressure, and the gas's composition, with denser gases generally transmitting sound faster.

27. What is the difference between gas adsorption and absorption?

Gas adsorption is the adhesion of gas molecules to a surface, forming a thin film. Absorption involves gas molecules entering the bulk of a liquid or solid material. Adsorption is a surface phenomenon, while absorption occurs throughout the volume of the absorbing material.

28. What is the kinetic molecular theory of gases?

The kinetic molecular theory explains gas behavior based on the motion of particles. It assumes that gas particles are in constant, random motion, have negligible volume, experience no attractive forces, and undergo perfectly elastic collisions. This theory helps explain gas laws and properties.

29. How does gas solubility in liquids change with temperature?

Generally, gas solubility in liquids decreases as temperature increases. This is because higher temperatures increase the kinetic energy of gas particles, making it easier for them to overcome intermolecular attractions with the liquid and escape into the gas phase.

30. What is Dalton's law of partial pressures?

Dalton's law states that the total pressure of a mixture of gases is equal to the sum of the partial pressures of each individual gas. Each gas in a mixture exerts pressure as if it were alone in the container, regardless of the presence of other gases.

31. How do gases behave differently at high altitudes compared to sea level?

At high altitudes, atmospheric pressure is lower due to fewer gas particles above. This results in lower oxygen partial pressure, making it harder to breathe. Gases also expand more readily at higher altitudes due to reduced external pressure.

32. What is the relationship between gas density and molecular mass?

Gas density is directly proportional to molecular mass when temperature and pressure are constant. Heavier gas molecules result in a denser gas, while lighter molecules produce a less dense gas. This relationship is described by the ideal gas law and molar mass concepts.

33. How does gas compression work, and why do gases heat up when compressed?

Gas compression involves reducing the volume of a gas by applying external pressure. As the gas is compressed, its particles are forced closer together, increasing collision frequency and transferring kinetic energy. This increased particle motion manifests as a temperature increase.

34. How do gas molecules behave differently in a vacuum compared to atmospheric conditions?

In a vacuum, gas molecules have more space to move freely with fewer collisions. They can travel longer distances without interacting with other particles. Under atmospheric conditions, gas molecules collide frequently with air molecules, limiting their mean free path.

35. What is the difference between a gas and a vapor?

A gas is a substance that exists entirely in the gaseous state at a given temperature, while a vapor is the gaseous form of a substance that is normally a liquid or solid at room temperature. Vapors can coexist with their liquid or solid phases, while gases cannot under normal conditions.

36. What is the relationship between gas volume and pressure at constant temperature?

The relationship between gas volume and pressure at constant temperature is described by Boyle's law. It states that the volume of a fixed amount of gas is inversely proportional to its pressure. As pressure increases, volume decreases, and vice versa, assuming constant temperature.

37. How do gases behave differently in space compared to on Earth?

In the vacuum of space, gases behave very differently than on Earth. Without atmospheric pressure, gases expand indefinitely. There are no collisions with air molecules, so gases disperse rapidly. The concept of pressure becomes irrelevant in the absence of a container or atmosphere.

38. How do gas laws help in weather prediction?

Gas laws help in weather prediction by explaining how temperature, pressure, and volume changes affect air masses. For example, the ideal gas law relates pressure, volume, and temperature, helping meteorologists understand how these variables interact to create weather patterns.

39. What is the difference between a compressed gas and a liquefied gas?

A compressed gas is stored under high pressure in its gaseous state, while a liquefied gas is stored as a liquid under pressure. Compressed gases (like oxygen) remain gaseous even under high pressure, while liquefied gases (like propane) become liquid when pressurized.

40. What is the relationship between gas particle speed and temperature?

The average speed of gas particles is directly related to temperature. As temperature increases, the kinetic energy of gas particles increases, causing them to move faster. This relationship is described by the Maxwell-Boltzmann distribution of molecular speeds.

41. How do gases behave in chemical reactions compared to liquids and solids?

Gases often react more readily than liquids or solids because their particles have more kinetic energy and are more spread out. This allows for easier collisions between reactant molecules. Gas reactions can also occur throughout the entire volume of a container, unlike surface-limited reactions in solids.

42. What is the significance of the critical point of a gas?

The critical point is the temperature and pressure above which a substance can no longer exist as separate liquid and gas phases. Beyond this point, the substance becomes a supercritical fluid with properties of both liquids and gases. Understanding the critical point is crucial in industrial processes and thermodynamics.

43. What is the difference between an atomsphere and a gas?

An atmosphere is a layer of gases surrounding a planet or celestial body, held in place by gravity. A gas is a state of matter characterized by particles with high kinetic energy and no fixed shape or volume. An atmosphere is composed of various gases, but not all gases form atmospheres.

44. How do gases behave in extreme conditions, such as in the core of gas giants?

In the extreme conditions found in gas giant cores, gases behave very differently from their normal state. Under immense pressure and temperature, hydrogen can become metallic, conducting electricity like a metal. These extreme conditions blur the lines between traditional states of matter.

45. How do gases contribute to the greenhouse effect on other planets?

Gases contribute to the greenhouse effect on other planets similarly to Earth. On Venus, for example, a thick atmosphere of carbon dioxide traps heat, leading to extremely high surface temperatures. On Mars, the thin CO₂ atmosphere provides a weak greenhouse effect.

46. What is the relationship between gas solubility and pressure?

Gas solubility in liquids generally increases with increasing pressure, as described by Henry's law. Higher pressure forces more gas molecules into solution. This principle is important in many applications, such as carbonated beverages and deep-sea diving physiology.

47. How do gases affect the properties of materials in industrial processes?

Gases can significantly affect material properties in industrial processes. For example, in metal heat treatment, controlled atmospheres of specific gases can alter surface properties. In semiconductor manufacturing, gases are used for doping and etching. Understanding gas-material interactions is crucial for many industrial applications.

48. What is the role of gases in the formation of nebulae?

Nebulae are vast clouds of gas and dust in space. They are primarily composed of hydrogen and helium gases, with traces of heavier elements. These gas clouds can be sites of star formation, with gravity causing the gas to collapse and form new stars. The gas composition and behavior in nebulae are crucial to understanding stellar evolution.

49. How do gases contribute to the Earth's magnetic field?

While gases don't directly create Earth's magnetic field, they play a role in its dynamics. The ionosphere, a layer of Earth's upper atmosphere containing ionized gases, interacts with the magnetic field. Solar wind, a stream of charged gas particles from the sun, also interacts with and shapes Earth's magnetosphere.

50. What is the difference between gas expansion and gas diffusion?

Gas expansion is the increase in volume of a gas when pressure decreases or temperature increases. Diffusion is the movement of gas particles from areas of high concentration to low concentration. Expansion relates to the overall volume change of a gas, while diffusion describes the mixing of gas particles within a space.

51. How do gases affect the formation and behavior of plasmas?

Plasmas, often called the fourth state of matter, are formed when gases are heated to extremely high temperatures or subjected to strong electromagnetic fields. The gas atoms become ionized, separating into electrons and positively charged ions. Understanding gas behavior is crucial for plasma physics and applications like fusion energy research.

52. What is the role of gases in the nitrogen cycle?

Gases play a crucial role in the nitrogen cycle. Atmospheric nitrogen gas (N₂) is fixed into biologically usable forms by certain bacteria. Nitrification and denitrification processes involve gaseous nitrogen compounds. Understanding these gas-phase transformations is essential for agriculture and environmental science.

53. How do gases contribute to the formation of planetary atmospheres?

Planetary atmospheres form through a combination of processes involving gases. These include outgassing from a planet's interior, capture of gases from the solar nebula during planet formation, and ongoing contributions from volcanic activity and impacts. The composition and retention of these gases depend on the planet's mass, temperature, and magnetic field.

54. What is the relationship between gas density and altitude in the atmosphere?

Gas density in the atmosphere decreases with increasing altitude. This is because the weight of the air above creates pressure, compressing the gas more at lower altitudes. As you go higher, there's less air above, resulting in lower pressure and density. This relationship is approximately exponential and is crucial for understanding atmospheric science and aviation.

55. How do gases behave differently in supercritical states?

In supercritical states, above a substance's critical point, gases behave as supercritical fluids. These fluids have properties of both liquids and gases: they can effuse through solids like a gas, but dissolve materials like a liquid. This unique behavior makes supercritical fluids useful in various applications, from decaffeination of coffee to green chemistry processes.