Question

what is standard temperature and pressure

Answer 1

273k =0°C is standard temperature and
1atm is standard pressure.........

Answer 2

• Standard temperature and pressure (STP) are standardized sets of settings for experimental observations that allow analyses between different data sets to be made.
• STP must not be mistaken with standard state typically utilized in thermodynamics calculations of a reaction's Gibbs energy.
• STP is the "standard" norm for determining gas density as well as volume.
• The standard temperature in degree centigrade is  zero or in kelvin scale is 273.15K.