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Melting Point
The melting point (or, rarely, liquefaction point) of a solid is the temperature at which it changes state from solid to liquid at atmospheric pressure. At the melting point the solid and liquid phase exist in equilibrium. The melting point of a substance depends on pressure and is usually specified at standard pressure. When considered as the temperature of the reverse change from liquid to solid, it is referred to as the freezing point or crystallization point. Because of the ability of some substances to supercool, the freezing point is not considered as a characteristic property of a substance
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Oil Bath
An oil bath is a type of heated bath used in a laboratory, most commonly used to heat up chemical reactions. It's essentially a container of oil that is heated by a hot plate or (in rare cases) a Bunsen burner.Contents1 Use 2 Hazards 3 In mechanics 4 See also 5 ReferencesUse[edit] These baths are commonly used to heat reaction mixtures more evenly than would be possible with a hot plate alone, as the entire outside of the reaction flask is heated. . Generally, silicone oil is used in modern oil baths, although mineral oil, cottonseed oil and even phosphoric acid have been used in the past.[1] Hazards[edit] Overheating the oil bath can result in a fire hazard, especially if mineral oil is being used. Generally, the maximum safe operating temperature of a mineral oil bath is approximately 160 oC, the oil's flash point. Mineral oil
Mineral oil
can't be used above 310oC in any cases, due to the compound's boiling point
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Agar
Agar
Agar
(pronounced /ˈeɪɡɑːr/, US: /ˈɑːɡər/) or agar-agar is a jelly-like substance, obtained from algae.[1] Agar
Agar
forms the supporting structure in the cell walls of certain species of algae, and which is released on boiling. These algae are known as agarophytes, and belong to the Rhodophyta
Rhodophyta
(red algae) phylum.[2][3] Agar
Agar
is actually the resulting mixture of two components: the linear polysaccharide agarose, and a heterogeneous mixture of smaller molecules called agaropectin.[4] Agar
Agar
has been used as an ingredient in desserts throughout Asia, and also as a solid substrate to contain culture media for microbiological work
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Absolute Zero
Absolute zero
Absolute zero
is the lower limit of the thermodynamic temperature scale, a state at which the enthalpy and entropy of a cooled ideal gas reaches its minimum value, taken as 0. Absolute zero
Absolute zero
is the point at which the fundamental particles of nature have minimal vibrational motion, retaining only quantum mechanical, zero-point energy-induced particle motion
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Pyrometer
A pyrometer is a type of remote-sensing thermometer used to measure the temperature of a surface. Various forms of pyrometers have historically existed. In the modern usage, it is a device that from a distance determines the temperature of a surface from the spectrum of the thermal radiation it emits, a process known as pyrometry and sometimes radiometry. The word pyrometer comes from the Greek word for fire, "πυρ" (pyro), and meter, meaning to measure. The word pyrometer was originally coined to denote a device capable of measuring the temperature of an object by its incandescence, visible light emitted by a body which is at least red-hot.[1] Modern pyrometers or infrared thermometers also measure the temperature of cooler objects, down to room temperature, by detecting their infrared radiation flux.Contents1 Design 2 History 3 Applications 4 See also 5 References 6 External linksDesign[edit] A modern pyrometer has an optical system and a detector
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Planck's Law
Planck's law
Planck's law
describes the spectral density of electromagnetic radiation emitted by a black body in thermal equilibrium at a given temperature T. The law is named after Max Planck, who proposed it in 1900. It is a pioneering result of modern physics and quantum theory. The spectral radiance of a body, Bν, describes the amount of energy it gives off as radiation of different frequencies. It is measured in terms of the power emitted per unit area of the body, per unit solid angle that the radiation is measured over, per unit frequency
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Emissivity
The emissivity of the surface of a material is its effectiveness in emitting energy as thermal radiation. Thermal radiation
Thermal radiation
is electromagnetic radiation and it may include both visible radiation (light) and infrared radiation, which is not visible to human eyes. The thermal radiation from very hot objects (see photograph) is easily visible to the eye. Quantitatively, emissivity is the ratio of the thermal radiation from a surface to the radiation from an ideal black surface at the same temperature as given by the Stefan–Boltzmann law. The ratio varies from 0 to 1. The surface of a black object emits thermal radiation at the rate of approximately 448 watts per square metre at room temperature (25 °C, 298.15 K); real objects with emissivities less than 1.0 emit radiation at correspondingly lower rates.[1] Emissivities are important in several contexts:insulated windows
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Pascal (unit)
The pascal (symbol: Pa) is the SI derived unit
SI derived unit
of pressure used to quantify internal pressure, stress, Young's modulus
Young's modulus
and ultimate tensile strength
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Carbon
Carbon
Carbon
(from Latin: carbo "coal") is a chemical element with symbol C and atomic number 6. It is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds. It belongs to group 14 of the periodic table.[13] Three isotopes occur naturally, 12C and 13C being stable, while 14C is a radionuclide, decaying with a half-life of about 5,730 years.[14] Carbon
Carbon
is one of the few elements known since antiquity.[15] Carbon
Carbon
is the 15th most abundant element in the Earth's crust, and the fourth most abundant element in the universe by mass after hydrogen, helium, and oxygen. Carbon's abundance, its unique diversity of organic compounds, and its unusual ability to form polymers at the temperatures commonly encountered on Earth
Earth
enables this element to serve as a common element of all known life
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Gibbs Free Energy
In thermodynamics, the Gibbs free energy
Gibbs free energy
( IUPAC
IUPAC
recommended name: Gibbs energy or Gibbs function; also known as free enthalpy[1] to distinguish it from Helmholtz free energy) is a thermodynamic potential that can be used to calculate the maximum of reversible work that may be performed by a thermodynamic system at a constant temperature and pressure (isothermal, isobaric). The Gibbs free energy(ΔGº = ΔHº-TΔSº) (J in SI units) is the maximum amount of non-expansion work that can be extracted from a thermodynamically closed system (one that can exchange heat and work with its surroundings, but not matter); this maximum can be attained only in a completely reversible process
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Enthalpy
Enthalpy
Enthalpy
/ˈɛnθəlpi/ ( listen) is a property of a thermodynamic system. The enthalpy of a system is equal to the system's internal energy plus the product of its pressure and volume.[1][2] The unit of measurement for enthalpy in the International System of Units (SI) is the joule. Other historical conventional units still in use include the British thermal unit (BTU) and the calorie. Enthalpy
Enthalpy
comprises a system's internal energy, which is the energy required to create the system, plus the amount of work required to make room for it by displacing its environment and establishing its volume and pressure.[3] Enthalpy
Enthalpy
is defined as a state function that depends only on the prevailing equilibrium state identified by the system's internal energy, pressure, and volume
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Entropy
In statistical mechanics, entropy (usual symbol S) is related to the number of microscopic configurations Ω that a thermodynamic system can have when in a state as specified by some macroscopic variables. Specifically, assuming for simplicity that each of the microscopic configurations is equally probable, the entropy of the system is the natural logarithm of that number of configurations, multiplied by the Boltzmann constant
Boltzmann constant
kB. Formally, S = k B ln ⁡ Ω  (assuming equiprobable states) . displaystyle S=k_ mathrm B ln Omega text (assuming equiprobable states) . This is consistent with 19th-century formulas for entropy in terms of heat and temperature, as discussed below
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Nucleation
Nucleation
Nucleation
is the first step in the formation of either a new thermodynamic phase or a new structure via self-assembly or self-organization. Nucleation
Nucleation
is typically defined to be the process that determines how long an observer has to wait before the new phase or self-organized structure appears. For example, if a volume of water is cooled (at atmospheric pressure) below 0° C, it will tend to freeze into ice. Volumes of water cooled only a few degrees below 0° C often stay completely ice free for long periods of time. At these conditions, nucleation of ice is either slow or does not occur at all. However, at lower temperatures ice crystals appear after little or no delay. At these conditions ice nucleation is fast.[1][2] Nucleation
Nucleation
is commonly how first-order phase transitions start, and then it is the start of the process of forming a new thermodynamic phase
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Fahrenheit
The Fahrenheit
Fahrenheit
scale is a temperature scale based on one proposed in 1724 by Dutch-German-Polish physicist Daniel Gabriel Fahrenheit (1686–1736).[1] It uses the degree Fahrenheit
Fahrenheit
(symbol: °F) as the unit
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Kelvin
The Kelvin
Kelvin
scale is an absolute thermodynamic temperature scale using as its null point absolute zero, the temperature at which all thermal motion ceases in the classical description of thermodynamics. The kelvin (symbol: K) is the base unit of temperature in the International System of Units
International System of Units
(SI). The kelvin is defined as the fraction ​1⁄273.16 of the thermodynamic temperature of the triple point of water (exactly 0.01 °C or 32.018 °F).[1] In other words, it is defined such that the triple point of water is exactly 273.16 K. The Kelvin
Kelvin
scale is named after the Belfast-born, Glasgow University engineer and physicist William Thomson, 1st Baron Kelvin (1824–1907), who wrote of the need for an "absolute thermometric scale". Unlike the degree Fahrenheit
Fahrenheit
and degree Celsius, the kelvin is not referred to or typeset as a degree
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Carboxylic Acids
A carboxylic acid /ˌkɑːrbɒkˈsɪlɪk/ is an organic compound that contains a carboxyl group (C(=O)OH).[1] The general formula of a carboxylic acid is R–COOH, with R referring to the rest of the (possibly quite large) molecule. Carboxylic acids occur widely and include the amino acids (which make up proteins) and acetic acid (which is part of vinegar and occurs in metabolism). Salts and esters of carboxylic acids are called carboxylates. When a carboxyl group is deprotonated, its conjugate base forms a carboxylate anion. Carboxylate
Carboxylate
ions are resonance-stabilized, and this increased stability makes carboxylic acids more acidic than alcohols
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