STP standard temperature

Another useful relationship is one derived from Avogadro s law 1 mol of any gas occupies 22.4 L at STP (standard temperature and pressure of 0°C (273 K) and 1 atm). If you can find the volume at STP, you can then convert it to moles using this relationship and then to grams, if needed. 

Interactions between neutral, nonpolar atoms or molecules are relatively weak, and can be accurately modeled by the Lennard-Jones potential discussed in the last section. Table 3.5 lists some specific examples. Notice that the well depth is less than 1% of typical bond energies in Table 3.2. In fact none of these atoms and molecules is condensed into a liquid at STP (standard temperature and pressure P = 1 atm, T = 273K). 

A gas is defined as any material that boils within the general ranges of STP standard temperature (25°C) and Pressure (l atmosphere). Although there are many compounds that satisfy these conditions, only ll elements do, and these are argon, chlorine, fluorine, helium, hydrogen, krypton, oxygen, neon, nitrogen, radon, and xenon. 

Of the three states of matter (solid, liquid, and gas), only gases have radically changing distances between molecules. When the distances between the molecules of a gas are different than what is found at STP (Standard Temperature and Pressure), we have either a positive or negative pressure (compared to atmospheric). 

Adsorption isotherms are plots of the amount of gas adsorbed at equilibrium as a function of the partial pressure p/p°, at constant temperature. The quantity of gas adsorbed is mainly expressed as the mass of gas (usually g) or the volume of gas reduced to STP (standard temperature and pressure). The majority of isotherms which result from physical adsorption may conveniently be grouped into five classes — the five types I to V included in the classification originally proposed by Brunauer, Deming, Deming and Teller — sometimes referred to simply as the Brunauer classification [2]. The essential features of these types are indicated in Fig. 12.1. 

STP standard temperature and SWG Standard Wire Gauge(Biit)... 

STP standard temperature and pressure for gases 0°C and 1 atm pressure, stress a change in conditions imposed on a system at equilibrium, strong acid an acid that reacts completely with water to form ions. 

The number of molecules in 1 cm of gas at STP (standard temperature, 0°C standard pressure, 760 torr) is 2.69 x 10 . All these molecules are in random motion but because of collisions between them the direction of motion changes frequently. The average distance traversed by a molecule between collisions is termed the mean free path. 

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