Question

What are the values of parameters like temperature and Pressure at STP and NTP?

Answer 1

Hint: If the volume of a gas does not change, the pressure of the gas is directly proportional to its absolute temperature (Amontons' law). At constant pressure, the volume of a given gas sample is directly proportional to its absolute temperature (Charles' law).

Complete answer:
STP-
Standard temperature and pressure are parameters that must be defined for experimental measurements in order to make distinctions between various sets of data. The International Union of Pure and Applied Chemistry (IUPAC) and the National Institute of Standards and Technology (NIST) are the most widely adopted standards, but they are not generally recognised. For their standard guide requirements, some organisations have developed a number of alternate meanings.
In 1982, the International Union of Pure and Applied Chemistry (IUPAC) revised the concept of standard temperature and pressure (STP) in chemistry.
Since 1982, STP is defined as a temperature of $ 273.15{\text{ }}K{\text{ }}\left( {0{\text{ }}^\circ C,{\text{ }}32{\text{ }}^\circ F} \right) $ and an absolute pressure of exactly $ {10^5}{\text{ }}Pa{\text{ }}\left( {100{\text{ }}kPa,{\text{ }}1{\text{ }}bar} \right) $ .
However, numerous technical publications (books, magazines, equipment and machinery advertisements) explicitly say "ordinary conditions" without elaborating, often replacing the word with the older "natural conditions," or "NC." In certain situations, this will lead to misunderstandings and mistakes. Temperature and pressure reference conditions are often used in good practise. If not specified otherwise, certain room temperatures are assumed to be similar to 1 atm pressure, 293 K $ \left( {20{\text{ }}^\circ C} \right) $ , and 0% humidity.

NTP-
A temperature of $ 20{\text{ }}^\circ C{\text{ }}\left( {293.15{\text{ }}K,{\text{ }}68{\text{ }}^\circ F} \right) $ and an absolute pressure of 1 atm was used by NIST $ \left( {14.696{\text{ }}psi,{\text{ }}101.325{\text{ }}kPa} \right) $ . This temperature and pressure standard is also known as normal temperature and pressure (abbreviated as NTP). NIST's reported STP values have not been checked, and a source is needed. However, values quoted in Carl S. Helrich's Modern Thermodynamics with Statistical Mechanics and Peter J. Linstrom's A Guide to the NIST Chemistry WebBook indicate that the STP used by NIST for thermodynamic studies is $ 298.15{\text{ }}K{\text{ }}\left( {77^\circ F} \right) $ and 1 bar $ \left( {14.5038{\text{ }}psi,{\text{ }}100{\text{ }}kPa} \right) $ .

Note:
Many experts and scientists who used the metric system of units before 1918 described the basic reference conditions for describing gas quantities as $ 15{\text{ }}^\circ C{\text{ }}\left( {288.15{\text{ }}K;{\text{ }}59.00{\text{ }}^\circ F} \right) $ and $ 101.325{\text{ }}kPa{\text{ }}\left( {1.00{\text{ }}atm;{\text{ }}760{\text{ }}Torr} \right) $ . The most widely used standard reference conditions for citizens using the imperial or U.S. customary methods during those years were $ 60{\text{ }}^\circ F{\text{ }}\left( {15.56{\text{ }}^\circ C;{\text{ }}288.71{\text{ }}K} \right) $ and 14.696 psi (1 atm), which were almost exclusively used for the oil and gas industries around the world. In any set of units, the aforementioned meanings are no longer the most widely used.