Difference Between Vapor and Gas: Vapor and Gas are two visually similar terms. While we are familiar with the concept that water transforms into vapor when it boils, we also encounter gases like oxygen in our surroundings. But is vapor synonymous with gas? Some characteristics of vapor and gas are similar while some are completely different.
In this article, we will explore the key difference between Vapor and Gas along with the physical and chemical properties of both states.
What is Vapor?
Vapors are gaseous forms of substance that are typically in liquid or solid form at room temperature. Vapors can be condensed means changing into liquid form only with a change of pressure without the requirement of a change in temperature/below their critical temperature. For example, we will consider a substance like water which has a critical temperature of 374 degrees C. But water changes into water vapor just by changing temperature.
Characteristics of Vapor
Here are the characteristics of Vapor such as its temperature, pressure, chemical reactions, etc:
- Formed through Phase change– As, told above they are substances that are typically in solid or liquid form but they change their form when pressure or high temperature is applied.
- Sensitive to temperature and Pressure– Vapors are highly dependent on temperature and pressure. Changes in these parameters can cause vapors to condense back into their liquid or solid form, or to transition into a gas. The behavior of vapors is strongly influenced by variations in these conditions.
- Follow some characteristics of gas – It also follows characteristics of gas such as having no definite shape or volume, having lower density and higher compressibility than liquid or solid, having higher kinetic energy and lower intermolecular forces than liquid or solid, and being able to undergo chemical reactions with other substances.
- Specific Examples– The most common example of vapor is water vapor and other substances that can be changed into liquid or gaseous form such as gasoline, alcohol, or volatile chemicals.
- Chemical Characteristics– Vapors follow the chemical properties of the substance from which they originate.
- Chemical reactions– Vapors can participate in chemical reactions just like their liquid or solid counterparts. For instance, volatile organic compounds in the vapor phase can react with atmospheric components, contributing to air pollution.
What is Gas?
Gas can be simply defined as the third state of matter, the other states are solid and liquid. We know that in solid and liquid the particles are tightly bound but in gas, they are free to move around. That’s why gas does not have a fixed structure. Gases also have a high degree of kinetic energy which allows them to move freely.
Characteristics of Gas
Here are the physical as well as chemical characteristics of Gas like its compressibility, fluidity, density, diffusion etc:
Physical Characteristics of Gas
The Physical Characteristics of Gas shown below in points:
- Expansion: Gases have the ability to expand and fill the entire volume of their container. This property is due to the high kinetic energy of gas particles, which causes them to move freely and independently.
- Compressibility: Gases are highly compressible. Their particles are relatively far apart, and increasing pressure can significantly reduce the volume they occupy.
- Fluidity: Gases flow easily and exhibit fluid-like behavior. They do not have a fixed shape or volume and can take the shape of their container.
- Low Density: Gases typically have low densities compared to liquids and solids because their particles are more dispersed.
- Diffusion and Effusion: Gas particles diffuse through each other and through small openings. Effusion is the process by which gas particles escape through a tiny hole.
- Pressure: Gases exert pressure on the walls of their container due to the constant collisions of gas particles with the container walls. This pressure can be measured in various units, including atmospheres (atm) and pascals (Pa).
- Temperature Dependence: The volume, pressure, and other properties of gases are highly temperature-dependent, as described by the ideal gas law (PV = nRT), where “T” is temperature in Kelvin.
Chemical Characteristics of Gas
The Chemical Characteristics of Gas shown below in points:
- Chemical Reactivity– Gases do react with other gases but this depends on there structure for example The reaction of sodium and water to form sodium hydroxide and hydrogen gas
- Solubility– Gases can dissolve in liquids, which is vital in processes like respiration, where oxygen is transported in the bloodstream.
- Catalysis: Gases are often involved in catalytic reactions, where a catalyst facilitates a chemical reaction without itself being consumed. This is common in industrial processes and automotive catalytic converters.
- Gaseous Laws– Gases do follow the gaseous laws such as Boyle’s law (P1V1 = P2V2), Charles’s law (V1/T1 = V2/T2), and Avogadro’s law, with help of with we can understand behavior of gases in different conditions
Difference Between Vapor and Gas
The points of difference between Vapor and Gas are shown below:
|
Vapor |
Gas |
|
|---|---|---|
|
Condensation |
A gaseous form of a substance that can be condensed into a liquid or a solid by increasing the pressure or decreasing the temperature |
A gaseous form of a substance that cannot be condensed into a liquid or a solid by increasing the pressure alone |
|
Phases |
Usually a mixture of two or more phases (liquid and gas) at room temperature |
Usually a single phase (gas) at room temperature |
|
State of Matter |
Not a state of matter, but a description of the physical state of a substance |
One of the four states of matter, along with solid, liquid, and plasma |
|
Formation |
Can be formed from any substance that can exist in both liquid and solid states, such as water, iodine, or carbon dioxide |
Can be formed from any substance that can exist in the gaseous state, such as oxygen, nitrogen, or helium |
|
Properties |
Has different vapor pressure, vapor density, flammability limits, etc. than gas |
Has constant vapor pressure, vapor density, flammability limits, etc. for a given temperature and pressure |
|
Scientific Differences |
Obey the Clausius-Clapeyron equation, which relates the vapor pressure and temperature of a substance |
Obey the ideal gas law, which relates the pressure, volume, temperature, and number of moles of a gas |
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Summary – Vapor vs Gas
Vapor and gas might seem similar, but they have some important differences. Vapor is a gaseous form of a substance that’s usually a liquid or solid at room temperature. It can change into a liquid or solid by tweaking pressure or temperature. On the other hand, gas is the third state of matter, and its particles freely move around. Gases can’t be easily turned into liquids just by changing pressure. Both have unique characteristics and play roles in chemical reactions. Understanding these differences helps us know how substances behave in different conditions, whether it’s water turning into vapor or oxygen existing as a gas.
FAQs on Difference Between Vapor and Gas
1. Write some examples of Vapor and Gas?
Some examples of gases are oxygen, nitrogen, helium, and hydrogen. They exist at gaseous state at room temperature and pressure and not too sensitive to pressure or temperature. Some examples of vapor are water vapor, iodine vapor, and carbon dioxide vapor. They exist as both liquid and gas at room temperature and there state can be changed by changing pressure or temperature.
2. Are gases and vapors visible to us with eyes?
Gases can be either visible or invisible, depending on factors like the presence of dust or vapor droplets within the gas. Vapors are often invisible as they consist of fine particles or molecules dispersed in the air.
3. What are various uses of Gases and Vapors in industries?
Gases can be used for wide range of purposes such as making chemicals, for welding, as refrigerants etc. While the vapors are used for distillation and drying in industries like pharmaceuticals and food processing.
4. What is effect of water vapor on atmosphere?
Water vapor is a major greenhouse gas and plays a crucial role in Earth’s climate. It can absorb and emit heat, affecting temperature and climate patterns, as well as influencing weather and precipitation.
5. Do Gas and Vapor have phase change?
Gases can change phase into liquids or solids by decreasing the temperature below their critical temperature, or by increasing the pressure above their critical pressure. While Vapors can change phase even below there critical temperature just by changing pressure.