Which of the following correctly defines standard temperature and pressure (STP) in chemistry?

• A. 273 K and 1 atm
• B. 0°C and 1 atm
• C. 0°C and 760 mmHg
• D. 25°C and 1 atm

Answer: (C)

Verified step by step guidance

1. Understand that Standard Temperature and Pressure (STP) is a set of conditions commonly used in chemistry to define a reference point for experiments and calculations involving gases.
2. Recall that temperature at STP is defined as 0 degrees Celsius, which is equivalent to 273 K (Kelvin). This is important because Kelvin is the SI unit for temperature in gas law calculations.
3. Recognize that pressure at STP is defined as 1 atmosphere (atm), which is the average atmospheric pressure at sea level.
4. Note that other units like 760 mmHg are equivalent to 1 atm, but the standard definition of STP uses atm for pressure and Kelvin for temperature.
5. Conclude that the correct definition of STP in chemistry is 273 K (0°C) and 1 atm pressure.