When did 25°C become standard temp and what is standard volume at that temp & 1 atm?

When I took Chemistry 1 mole of gas filled 22.4 L at 20°C and 760 mmHg (Torr.)

When did 25°C become standard temp and what is standard volume at that temp %26amp; 1 atm?
25 C is near room temperature. It is about 77 F. Many lab experiments are just to be performed near this temperature (it is usually cooler depending on the place and time of year.0


And your second statement is correct. 1 mole of gas filled 22.4 L at 20°C and 760 mmHg (Torr.). You can prove this using the ideal gas law, PV=nRT.


I am not sure if 22.4 L is at 20 or 25 C but the error here would be (293/298 = 0.98), ie. very small. Note, I converted temp to Kelvin.
Reply:25 deg C is standard room temperature; STP is still 0 deg C and 1 atm (760mm Hg or 760 torr)





V = nRT/P


V = 1x0.08206x298.15 / 1 = 24.466 L (at 25 deg C)