What is the difference between STP and NTP?

STP stands for Standard Temperature and Pressure, and NTP stands for Normal Temperature and Pressure.

STP stands for Standard Temperature and Pressure.NTP stands for Normal Temperature and Pressure.

STP is set by the IUPAC as 0°C and 100 kPa or 1 bar.

Many old books and online sources say that standard pressure is 101.325 kPa (the old IUPAC standard that was changed in 1982), but I defer to the current IUPAC standard of 100 kPa.

NTP is set at 101.325 kPa but uses 20°C as the temperature.

Note: 0°C = 273.15K 20°C = 293.15K

In simple language:

STP stands for Standard Temperature and Pressure. NTP stands for Normal Temperature and Pressure.

At STP: ##color(white)(l)"Pressure = 1 bar = 0.987 atm"## ##color(white)(mmmll)"Temperature = 273 K or 0°C"##

At NTP: ##"Pressure = 1 atm"## ##color(white)(mmmll)"Temperature = 293 K or 20°C"##

Also, 1 atm = 1.013 bar 1 atm = 76.0 cm 1 atm = 0.760 m

Here, cm = centimetre m = metre atm = atmosphere