What is standard temperature and pressure?
In chemistry, physics and engineering, the term “standard temperature and pressure” (STP) concerns the standard set of gas conditions as the basis for calculations. There are several definitions for standard temperatures and pressures and the values of these links will depend on the required applications, industrial or academic environments. The most common set of standards was the temperature of 32 degrees Fahrenheit (0 degrees Celsius) and pressure of 1 atmosphere or 101.325 kilopascals (KPA), although pressure of 1 bar or 100 kPa currently accepts the International Association of Pure and Applied Chemistry). Standard pressure reflects the accepted average atmosphere pressure on the sea level and the standard temperature reflects the freezing point of clean water at this pressure.
Standard conditions are most commonly used to calculate gas in chemistry and engineering. For example, it is possible to calculate molar volumetric gas at standard temperature and pressure through the Act on the Ideal Gas. In engineering, standard conditions can be used to calculate the mass flowGases on the basis of standard volume flows from flow meters.
The ideal gas Act shows the relations between pressure (P), volume (V) and temperature (t) for ideal gas. It can be expressed as PV = nrt, and n refers to the number of gas moths and r with reference to the ideal gaseous constant. Using current standard temperature and pressure, as defined by IUPAC, will have 1 mol ideal gas volume 1 385.9 cubic inches (22.711 liters).
Standard temperature and pressure may actually apply to many different conditions used by different industries. For example, a engineering company could decide to use 1 atmosphere and 77 degrees Fahrenheit (25 degrees Celsius) as a standard temperature and Lisure better reflect the surrounding conditions of the area. For example, oil engineers define standard conditions such as 59 degrees Fahrenheit (15 degrees Celsius) and 1 bar.When working with engineering designs, it is important that one understands the intended standards of the designer.
differences in received values for standard temperature and pressure may depend on regional conditions. Higher pressures and temperatures make greater sense of laboratories and industries located in areas subject to long periods of hot weather. Lower pressures can be used for laboratories at high altitudes. Of course, the differences in the received values could also be caused by personal preferences of chemists, laboratory technicians and engineers.