Standard temperature and pressure (STP)

Definition

Standard Temperature and Pressure (STP) is a reference point used in chemistry to define a set of conditions for experimental measurements. It is defined as a temperature of 0°C (273.15 K) and a pressure of 1 atm.

5 Must Know Facts For Your Next Test

1. STP is commonly used when performing gas law calculations to ensure consistency.
2. At STP, one mole of an ideal gas occupies 22.414 liters.
3. The temperature at STP is 0 degrees Celsius or 273.15 Kelvin.
4. The pressure at STP is 1 atmosphere, which is equivalent to 101.325 kPa.
5. STP conditions are different from standard state conditions, which are typically used for thermodynamic calculations.

Review Questions

• What are the temperature and pressure values defined by STP?
• How many liters does one mole of an ideal gas occupy at STP?
• Why are STP conditions important in gas law calculations?

Related terms

Ideal Gas Law: An equation of state for an ideal gas: $PV=nRT$, where $P$ is pressure, $V$ is volume, $n$ is number of moles, $R$ is the gas constant, and $T$ is temperature.

Molar Volume: The volume occupied by one mole of a substance. For an ideal gas at STP, this volume is 22.414 liters.

Boyle's Law: $PV=k$, where $k$ is a constant for a given amount of gas at constant temperature; it describes the inverse relationship between pressure and volume.