Which of the following sets of conditions correctly represents standard temperature and pressure (STP)?

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

Answer: (D)

Verified step by step guidance

1. Understand that Standard Temperature and Pressure (STP) is a set of conditions commonly used as a reference in chemistry to describe gases.
2. Recall that the standard temperature is defined as 0°C, which is equivalent to 273 K. This is important because temperature in gas law calculations must be in Kelvin.
3. Recognize that the standard pressure at STP is 1 atmosphere (atm), which is also equivalent to 760 mmHg or 760 torr.
4. Compare each given condition to the standard values: 0°C (273 K) for temperature and 1 atm (or 760 mmHg) for pressure.
5. Conclude that the correct sets of conditions representing STP are those that combine 0°C (or 273 K) with 1 atm (or 760 mmHg) pressure.