A volumetric flask (vol flask for short) is a piece of laboratory glassware used to measure a very precise and accurate amount of a liquid, and is used for such when the amount is too big for a pipette or burette. It is shaped like a Florence flask with a flatter bottom so as to not tip over. The neck is marked (usually by a scratch or etch on the glass) at a very precise measurement. When the liquid has been added to that point (so the bottom of the meniscus is on the line), it is usually accurate to within a small fraction of ...
Cash usually refers to money in the form of currency, such as bills or coins.
Cash - Etymology.
The word comes from kachu in the Indian language Tamil.
Cash - Usage.
Cash can also refer to checks, money orders, cashier's checks, bank drafts, or traveler's checks. In all these forms, the term indicates the most liquid form of assets, which have a fixed value and can be easily converted to currency. "Cash pay" (as opposed to, e.g., stock options) would almost ...
Chemistry (derived from the Arabic word kimia, alchemy, where al is Arabic for the) is the science of matter that deals with the composition, structure, and properties of substances and with the transformations that they undergo. In the study of matter, chemistry also investigates its interactions with energy and itself (see physics, biology). Because of the diversity of matter, which is mostly composed of different combinations of atoms, chemists often study how atoms of different chemical elements interact to fo ...
Hail is a type of graupel, a form of precipitation, composed of spears or irregular lumps of ice. It occurs when supercooled water droplets (remaining in a liquid state despite being below the freezing point, 0 °C/32 °F) in a storm cloud aggregates around some solid object, such as a dust particle or an already-forming hailstone. The water then freezes around the object. Depending on the wind patterns within the cloud, the hailstone may continue to circulate for some time, increasing in size. Eventually, the hailstone falls to the ground, when the updraft is no ...
A gas is one of the four main phases of matter (after solid and liquid, and followed by plasma), that subsequently appear as a solid material is subjected to increasingly higher temperatures. Thus, as energy in the form of heat is added, a solid (e.g. ice) will first melt to become a liquid (e.g. water), which will then boil or evaporate to become a gas (e.g. water vapor). In some circumstances, a solid (e.g. "dry ice") can directly turn into a gas: this is called sublimation. If the gas is further heated, its atoms or molecules can become (wholly or partiall ...
Frost, like snow, is the result of deposition of water vapor in saturated air. If solid surfaces in contact with the air are chilled below the deposition point (see frost point), then spicules of ice grow out from the solid surface. The size of the crystals is dependent on time and the amount of water vapor available.
Frost is often observed around cracks in wooden sidewalks due to the moist air escaping from the ground below. Other objects on which frost develops are those with low specific heat and high thermal emissivity, su ...
Wind chill is the apparent temperature felt on exposed skin due to the combination of air temperature and wind speed. Except at higher temperatures, where wind chill is considered less important, the wind chill temperature (often incorrectly called the "wind chill factor") is always lower than the air temperature, because any wind increases the rate at which moisture evaporates from the skin and carries heat away from the body. The phase change of water (in sweat) from liquid to vapor requires that the molecules reach a higher energy state. That energy is acquired by absorbing heat from surr ...
Cloud condensation nuclei or CCNs are small particles (typically 0.00002 mm, or 1/100 th the size of a cloud droplet [1]) about which cloud droplets coalesce. Water requires a solid surface to make the transition from a vapour to a liquid. In the atmosphere, this surface presents itself as tiny solid particles called CCNs. When no CCNs are present, water vapour can be supercooled below 0 °C (32 °F) before droplets spontaneously form (this is th ...
Evaporation is the process whereby atoms or molecules in a liquid state (or solid state if the substance sublimes) gain sufficient energy to enter the gaseous state.
The thermal motion of a molecule must be sufficient to overcome the surface tension of the liquid in order for it to evaporate, that is, its kinetic energy must exceed the work function of cohesion at the surface. Evaporation therefore proceeds more quickly at higher temperature and in liquids with lower surface tension. Since only a small proportion of the molecul ...
Vapor (US English) or vapour (British English) is the gaseous state of matter.
Although vapor and gas are frequently used interchangeably, vapor often carries the connotation of gaseous matter in a state of equilibrium with identical matter in a liquid or solid state below its boiling point. See the entry on vapor pressure for more information on this topic.
The constituent atoms or molecules of ...
The boiling point of a substance is the temperature at which it can change 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 vaporization. However, evaporation is a surface phenomenon, in which only molecules located near the gas/liquid surface could evaporate. Boiling on the other hand is a bulk process, so at the boiling point molecules anywhere in the liquid may be vap ...
Water has the chemical formula H2O, meaning that one molecule of water is composed of two hydrogen atoms and one oxygen atom. It is in dynamic equilibrium between the liquid and solid states at standard temperature and pressure. At room temperature, it is a nearly colorless, tasteless, and odorless liquid. It is often referred to in the sciences as the universal solvent and the only pure substance found naturally in all three states of matter.
Water molecule - Forms of water.
See ...
In chemistry and condensed matter physics, a critical point, also called a critical state, specifies the conditions (temperature, pressure) at which the liquid state of the matter ceases to exist. As a liquid is heated, its density decreases while the pressure and density of the vapor being formed increases. The liquid and vapor densities become closer and closer to each other until the critical temperature is reached where the two densitie ...
The critical temperature, Tc, of a material is the temperature above which distinct liquid and gas phases do not exist. As the critical temperature is approached, the properties of the gas and liquid phases become the same. Above the critical temperature, there is only one phase. The critical pressure is the vapor pressure at the critical temperature. The critical molar volume is the volume of one mole of material at the critical temperature and pressure. On diagrams showing thermodynamic properties for a given substance, the point at critical temperature and criti ...
Ultraviolet-Visible Spectroscopy or Ultraviolet-Visible Spectrophotometry (UV/ VIS) involves the spectroscopy of photons (spectrophotometry). It uses light in the visible and adjacent near ultraviolet (UV) and near infrared (NIR) ranges. In this region of energy space molecules undergo electronic transitions.
UV/VIS spectroscopy - Beer-Lambert Law.
The method is used in a quantitative way to determine concentrations of an absorbing species in solution, using the Beer-Lambert law:
...
Cyanic acid is a colourless poisonous liquid with a boiling point of 23.5°C and a melting point of -81°C. At 0°C cyanic acid is converted to cyamelide.
In water, cyanic acid hydrolyses to carbon dioxide and ammonia.
Cyanic acid (H-N=C=O) is an isomer of fulminic acid (H-C=N-O).
Two tautomers exist for cyanic acid, NC-O-H and H-N=C=O .
It forms in a reaction between potassium cyanate and formic acid.< ...
The water cycle—technically known as the hydrologic cycle—is the circulation of water within the earth's hydrosphere, involving changes in the physical state of water between liquid, solid, and gas phases. The hydrologic cycle refers to the continuous exchange of water between atmosphere, land, surface and subsurface waters, and organisms. In addition to storage in various compartments (the ocean is one such "compartment"), the multiple cycles that make up the earth's water cycle involve five main physical act ...
Waterworld was a 1995 film that was co-produced by Kevin Costner and directed by Kevin Reynolds. Problems encountered during filming massively escalated its budget, and it held the unfortunate distinction of being the most expensive film ever made (at the time), causing some critics to dub the movie "Fishtar" and "Kevin's Gate" (references to the notorious flops Ishtar and Heaven's Gate). With a budget of $175 million, the film only grossed a meager $88 million at the U.S. box office, and was initially considered ...
Changelings are an alien race from the Star Trek universe. They are called Changelings because of their ability to shape-shift. The Changelings were introduced in the Star Trek spin-off Star Trek: Deep Space Nine. Constable Odo, one of the regular characters on that show, is a Changeling.
Their natural state is a liquid protoplasm. The Female Shapeshifter once told Odo that their race once had bodies similar to those of other species, but they had since evolved beyond those physical bodies. Changelings have the ability to meld ...
Chromatography is a family of analytical chemistry techniques for the separation of mixtures. It involves passing the sample, a mixture which contains the analyte, in the "mobile phase", often in a stream of solvent, through the "stationary phase." The stationary phase retards the passage of the components of the sample. When components pass through the system at different rates they become separated in time, like runners in a mass-start foot race. Each component has a characteristic time of passage through the system, called a "retention time." Chromatographic separation is achieved when the retention time of the analyte ...
Hydrogen atoms on water or hydroxide (OH) can be involved in hydrogen bonds or be dangling. Wet electrons are primarily stabilized by by the dangling atoms on OH, which is more acidic than water, but the dangling atoms on water also contribute to the stabilization.
If you wanted to go from one valley to another and there was an intervening mountain, you would probably take the lowest elevation pathway that would require the minimum amount of work. To transport an electron from solid to liquid, the minimum amount of energy you would ha ...
Condensation is the change in phase of a substance to a denser phase, such as gas (or vapor) to a liquid. Condensation commonly occurs when a vapor is cooled to a liquid, but can also occur if a vapor is compressed (i.e., pressure on it increased) into a liquid, or undergoes a combination of cooling and compression. Liquid which has been condensed from a vapor is called condensate. A device or unit used to condense vapors into liquid is called a condenser. Condensers are typically coolers or heat exchangers w ...
