Question

what is value is stp

Answer 1

Temperature at STP is 273K
Pressure at STP is 760 mm of Hg(Mercury)
Volume at STP is 22.4 litres

Answer 2

STP stands for
standard temperature and pressure
. Because gases occupy different volumes at different temperatures and pressures, it is necessary to define a set of conditions that can be considered standard.
At STP:
The temperature is 0°C or 273 K
The pressure is 1 atmosphere or 760 mmHg or 760 torr
One mole of any gas occupies 22.4 L of volume (molar volume)