Normal temperature and pressure

As excited atoms, molecules, or ions come to equilibrium with their surroundings at normal temperatures and pressures, the extra energy is dissipated to the surroundings. This dissipation causes the particles to slow as translational energy is lost, to rotate and vibrate more slowly as rovibrational energy is lost, and to emit light or x-rays as electronic energy is lost. 

The loss of energy returns the particles to their original (ground) state, viz., their energy state at normal temperatures and pressures. 

Liquefied natural gas (LNG) also plays a large role in both the transportation and storage of natural gas. At a pressure of 101.3 kPa (1 atm), methane can be Hquefted by reducing the temperature to about — 161°C. When in the Hquid form, methane occupies approximately 1/600 of the space occupied by gaseous methane at normal temperature and pressure. In spite of the very low temperature of the Hquid, LNG offers advantages for both shipping and storing natural gas. 

Vinyl chloride (also known as chloroethylene or chloroethene) is a colorless gas at normal temperature and pressure, but is typically handled as the hquid (bp —13.4° C). However, no human contact with the Hquid is permissible. Vinyl chloride is an OSHA-regulated material. 

Materials that on shor t exposure could cause death or major residual injury 4 Materials that will rapidly or completely vaporize at atmospheric pressure and normal ambient temperature, or that are readily dispersed in air and will burn readily 4 Materials that in themselves are readily capable of detonation or of explosive decomposition or reaction at normal temperatures and pressures... 

Barometric pressure at standard temperature and pressure = 101.325 kPa Standard temperature and pressure (STP) = 0 °C at 101.325 kPa (also known as normal temperature and pressure)... 

Normal temperature and pressure (NTP) See Standard temperature and pressure (STP). 

The hydrogen number is defined as the number of c.c. of hydrogen corrected to normal temperature and pressure absorbed by 1 gram of the material during the period of rapid absorption. This number gives a measure of the proportion of active constituent present, but the results... 

Ionisation detectors. An important characteristic of the common carrier gases is that they behave as perfect insulators at normal temperatures and pressures. The increased conductivity due to the presence of a few charged molecules in the effluent from the column thus provides the high sensitivity which is a feature of the ionisation based detectors. Ionisation detectors in current use include the flame ionisation detector (FID), thermionic ionisation detector (TID), photoionisation detector (PID) and electron capture detector (ECD) each, of course, employing a different method to generate an ion current. The two most widely used ionisation detectors are, however, the FID and ECD and these are described below. 

A = observed density of partially dissociated gas, d = density of completely dissociated gas, all reduced to normal temperature and pressure. 

The normal state is the state of the element at normal temperature and pressure (20°C and 1 atm), s denotes solid, 1, liquid, and g, gas m denotes metal, nm, nonmetal, and md, metalloid. 

Of the compounds listed in Table 10.1, all except dimethoate and azinphos-methyl exist as liquids at normal temperature and pressure. Looking through the table, it can be seen that there is considerable variation in both water solubility and vapor... 

Stainless steel, mild steel under normal temperature and pressure Silver, platinum and tantalum, carbon, graphite for wet gas. At higher pressures use extra heavy black iron pipe. High-pressure steel. Monel or aluminium-iron-bronze valves... 

We know that ammonia is a gas at normal temperature and pressure, so it is sensible that the temperature must be lowered substantially to ran a reaction in liquid ammonia. Knowing that ammonia is liquid at 0.50 atm and 220 K, it makes sense that a still lower pressure is required to boil off the liquid at this temperature. 

A substance such as propane with a critical temperature of 370 K has a measurable vapor pressure of 998000 Pa, or approximately 10 atm at 27°C, which exceeds atmospheric pressure of 101325 Pa, the boiling point being -42"C or 231 K. It is thus a vapor at normal temperatures and pressures. A Henry s law constant can be calculated from this vapor pressure and a solubility as described earlier. 

Oral LD50 data are recorded where they are available (— indicates a toxicity listing but no oral toxicity data). Where the material is a gas at normal temperatures and pressure (25°C and 1 atm), the atmospheric-pressure boiling point is given. 

Condensate is normally considered the entrapped liquids in process or production gas streams due to temperature or pressure, in the typically in the range of C3, C4, C5 or heavier hydrocarbon liquids. It is also known as natural gasoline C5 plus and pentanes plus, and as a liquid at normal temperatures and pressures it generally consists of a mixture of the C5 (pentanes) and heavier hydrocarbons. It is normally condensed (i.e., by expansion and cooling of the gas) out of the process stream in primary separation processes, where it is then sent to other refinery processes to further separate the condensate into its primary fractions, i.e., propane, butane, and liquids constituents. 

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