Ideal gas

An ideal gas is a gas whose pressure P, volume V, and temperature T are related by the ideal gas law

PV = nRT .

where:
P is the pressure of the gas
V is the volume of the gas
n is the amount of substance of gas (also known as number of moles)
R is the ideal, or universal, gas constant, equal to the product of the Boltzmann constant and the Avogadro constant = 8.3145 J/mol K.
T is the temperature of the gas

At normal conditions such as standard temperature and pressure, most real gases behave qualitatively like an ideal gas. Many gases such as nitrogen, oxygen, hydrogen, noble gases, and some heavier gases like carbon dioxide can be treated like ideal gases within reasonable tolerances. Generally, a gas behaves more like an ideal gas at higher temperature and lower pressure, as the work which is against intermolecular forces becomes less significant compared with the particles' kinetic energy, and the size of the molecules becomes less significant compared to the empty space between them.

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Boiling point

The boiling point of a substance is the temperature at which it turns its state from a liquid to a gas throughout the bulk of the liquid.

A liquid may change to a gas at temperatures below the boiling point through the process of evaporation.

Any change of state from a liquid to a gas at boiling point is considered boiling.

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Energy

Energy

In physics, energy is the ability of a body or system to do work or produce a change; or is a property of objects that is transferable among them via fundamental interactions, which can be converted in form but not created or destroyed and expressed usually in joules or kilowatt hours (kWh).

The joule is the SI unit of energy, based on the amount transferred to an object by the mechanical work of moving it 1 metre against a force of 1 newton.

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Heat

Heat

Heat is the condition or quality of being hot or cold. In other words, the degree of hotness or coldness of a body or environment is termed as heat.

In physics, heat is a form of energy associated with the motion of atoms or molecules and capable of being transmitted through solid and fluid media by conduction, through fluid media by convection, and through empty space by radiation. The higher the temperature of a material, the faster the atoms are moving, and hence the greater the amount of energy present as heat.

See also Temperature 

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Isolated system

Isolated system

An isolated system is one devoid of interactions of any kind with the surroundings (including mass exchange, heat, and work interactions).

An isolated system cannot exchange any heat, work, or matter with the surroundings, while an open system can exchange all heat, work and matter; a closed system can exchange only energy(as heat or work) but not matter, with its surroundings.

Open-Close-Isolated System

See also Open and Close System.

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Open system and Close system

Close system

In thermodynamics, a closed system can exchange energy (as heat or work) but not matter, with its surroundings.
A closed system is one in which no mass crosses the system boundaries, but energy can cross the system boundary in form of heat and work.

Open-Close-Isolated System

Open system

An open system can exchange all heat, work and matter, with its surroundings.
An open system is one in which mass crosses the system boundaries. The system may gain or lose mass or simply have some mass pass through it.

See also Isolated system.

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Chemistry

Chemistry is a branch of physical science that studies the composition, structure, properties and change of matter. Chemistry is chiefly concerned with atoms and molecules and their interactions and transformations, for example, the properties of the chemical bonds formed between atoms to create chemical compounds. As such, chemistry studies the involvement of electrons and various forms of energy in photochemical reactions, oxidation-reduction reactions, changes in phases of matter, and separation of mixtures. Preparation and properties of complex substances, such as alloys, polymers, biological molecules, and pharmaceutical agents are considered in specialized fields of chemistry.

Chemistry is sometimes called the central science because it bridges other natural sciences like physics, geology and biology. Chemistry is a branch of physical science but distinct from physics.

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Chemical reaction

A chemical reaction is a process that leads to the transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the positions of electrons in the forming and breaking of chemical bonds between atoms, with no change to the nuclei (no change to the elements present), and can often be described by a chemical equation.

A chemical reaction is a chemical change which forms new substances.

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Unit operation

In chemical engineering and related fields, a unit operation is a basic step in a process. Unit operations involve a physical change or chemical transformation such as separation, crystallization, evaporation, filtration, polymerization, isomerization, and other reactions. For example, in milk processing, homogenization, pasteurization, chilling, and packaging are each unit operations which are connected to create the overall process.

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Volatility

In chemistry and physics, volatility is the tendency of a substance to vaporize. Volatility is directly related to a substance's vapor pressure. At a given temperature, a substance with higher vapor pressure vaporizes more readily than a substance with a lower vapor pressure.

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Condensation

Condensation is the change of the physical state of matter from gas phase into liquid phase, and is the reverse of vaporization. It can also be defined as the change in the state of water vapor to liquid water when in contact with any surface. When the transition happens from the gaseous phase into the solid phase directly, the change is called deposition.

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Distillation

Distillation is a process of separating the component substances from a liquid mixture by selective vaporization and condensation. Distillation may result in essentially complete separation (nearly pure components), or it may be a partial separation that increases the concentration of selected components of the mixture. In either case the process exploits differences in the volatility of mixture's components. In industrial chemistry, distillation is a unit operation of practically universal importance, but it is a physical separation process and not a chemical reaction.

Laboratory display of distillation: 1: A source of heat 2: Still pot 3: Still head 4:Thermometer/Boiling point temperature 5: Condenser 6: Cooling water in 7:Cooling water out 8: Distillate/receiving flask 9: Vacuum/gas inlet 10: Still receiver 11: Heat control 12: Stirrer speed control 13: Stirrer/heat plate 14:Heating (Oil/sand) bath 15: Stirring means e.g. (shown), boiling chips or mechanical stirrer 16: Cooling bath.

Automatic Distillation Unit for the determination of the boiling range of petroleum products at atmospheric pressure

Diagram of a typical industrial distillation tower

Section of an industrial distillation tower showing detail of trays with bubble caps

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Evaporation

Evaporation is a type of vaporization of a liquid that occurs from the surface of a liquid into a gaseous phase that is not saturated with the evaporating substance. 

See more on vaporization

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Vaporization

Vaporization (or vaporisation in British English) of an element or compound is a phase transition from the liquid phase to vapor. There are two types of vaporization: evaporation and boiling.

This diagram shows the nomenclature for the different phase transitions.

Evaporation is a phase transition from the liquid phase to vapor ( a state of substance below critical temperature and critical pressure) that occurs at temperatures below the boiling temperature at a given pressure. Evaporation usually occurs on the surface. Evaporation may occur when the partial pressure of vapor of a substance is less than the equilibrium vapour pressure.

Boiling is a phase transition from the liquid phase to gas phase that occurs at or above the boiling temperature. Boiling, as opposed to evaporation, occurs below the surface. Boiling occurs when the equilibrium vapour pressure of the substance is greater than or equal to the environmental pressure. For this reason, boiling point varies with the pressure of the environment.Evaporation is a surface phenomenon whereas boiling is a bulk phenomenon.

Sublimation is a direct phase transition from the solid phase to the gas phase, skipping the intermediate liquid phase.

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Mixture

In chemistry, a mixture is a material system made up of two or more different substances which are mixed but are not combined chemically. A mixture refers to the physical combination of two or more substances on which the identities are retained and are mixed in the form of solutions, suspensions, and colloids.

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Separation

In chemistry and chemical engineering, a separation process, or a separation technique, or simply a separation, is a method to achieve any mass transfer phenomenon that converts a mixture of substances into two or more distinct product mixtures, at least one of which is enriched in one or more of the mixture's constituents. In some cases, a separation may fully divide the mixture into its pure constituents. Separations are carried out based on differences in chemical properties, or physical properties such as size, shape, mass, density, or chemical affinity, between the constituents of a mixture, and are often classified according to the particular differences they use to achieve separation.

List of separation techniques

• Adsorption, adhesion of atoms, ions or molecules of gas, liquid, or dissolved solids to a surface
• Centrifugation and cyclonic separation, separates based on density differences
• Chromatography separates dissolved substances by different interaction with (i.e., travel through) a material
• Crystallization
• Decantation
• Demister (vapor), removes liquid droplets from gas streams
• Distillation, used for mixtures of liquids with different boiling points
• Drying, removes liquid from a solid by vaporisation
• Electrophoresis, separates organic molecules based on their different interaction with a gel under an electric potential (i.e., different travel)
• Elutriation
• Evaporation
• Extraction
  • Leaching
  • Liquid-liquid extraction
  • Solid phase extraction
• Flotation
  • Dissolved air flotation, removes suspended solids non-selectively from slurry by bubbles that are generated by air coming out of solution
  • Froth flotation, recovers valuable, hydrophobic solids by attachment to air bubbles generated by mechanical agitation of an air-slurry mixture, which float, and are recovered
  • Deinking, separating hydrophobic ink particles from hydrophilic paper pulp in paper recycling
• Flocculation, separates a solid from a liquid in a colloid, by use of a flocculant, which promotes the solid clumping into flocs
• Filtration – Mesh, bag and paper filters are used to remove large particulates suspended in fluids (e.g., fly ash) while membrane processes including microfiltration,ultrafiltration, nanofiltration, reverse osmosis, dialysis (biochemistry) utilising synthetic membranes, separates micrometre-sized or smaller species
• Fractional distillation
• Fractional freezing
• Oil-water separation, gravimetrically separates suspended oil droplets from waste water in oil refineries, petrochemical and chemical plants, natural gas processing plants and similar industries
• Magnetic separation
• Precipitation
• Recrystallization
• Sedimentation, separates using vocal density pressure differences
  • Gravity separation
• Sieving
• Stripping
• Sublimation
• Vapor-liquid separation, separates by gravity, based on the Souders-Brown equation
• Winnowing
• Zone refining

Separations based on phase equilibria

gas-liquid	gas-solid	liquid-solid	liquid-liquid	supercritical fluid-solid	supercritical fluid-liquid
distillation	adsorption	precipitation	extraction	supercritical-fluid chromatography	supercritical-fluid extraction
gas-liquid chromatography	sublimation	zone melting	partition chromatography
foam fractionation		crystallization
		ion exchange
		adsorption
		exclusion
		clathration

Separations based on rate phenomena

barrier separations	field separations
membrane filtration	electrophoresis
dialysis	ultracentrifugation
ultrafiltration	electrolysis
electrodialysis	field-flow fractionation
reverse osmosis

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Fluid

In physics, a fluid is a substance that continually deforms (flows) under an applied shear stress.

A fluid is either a liquid or a gas.

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Pressure

Pressure (symbol: p or P) is the ratio of force to the area over which that force is distributed.

Pressure is force per unit area applied in a direction perpendicular to the surface of an object.

Definition

Pressure is the amount of force acting per unit area. The symbol of pressure is p or P.

Mathematically:

where:

 is the pressure,

 is the normal force,

 is the area of the surface on contact.

.

Units[edit]

The SI unit for pressure is the pascal (Pa), equal to one newton per square metre (N/m² or kg·m⁻¹·s⁻²)

Pressure units

v t e	Pascal	Bar	Technical atmosphere	Standard atmosphere	Torr	Pounds per square inch
	(Pa)	(bar)	(at)	(atm)	(Torr)	(psi)
1 Pa	≡ 1 N/m2	10−5	1.0197×10−5	9.8692×10−6	7.5006×10−3	1.450377×10−4
1 bar	105	≡ 106 dyn/cm2	1.0197	0.98692	750.06	14.50377
1 at	0.980665×105	0.980665	≡ 1 kp/cm2	0.9678411	735.5592	14.22334
1 atm	1.01325×105	1.01325	1.0332	≡ p0	≡ 760	14.69595
1 Torr	133.3224	1.333224×10−3	1.359551×10−3	1.315789×10−3	≈ 1 mmHg	1.933678×10−2
1 psi	6.8948×103	6.8948×10−2	7.03069×10−2	6.8046×10−2	51.71493	≡ 1 lbF/in2

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