At what temperature does pure water boil at standard atmospheric pressure (1 atm)?

• A. 212 °C
• B. 100 °C
• C. 50 °C
• D. 0 °C

Answer: (B)

Verified step by step guidance

1. Understand that the boiling point of a liquid is the temperature at which its vapor pressure equals the external pressure. For water at standard atmospheric pressure (1 atm), this is the temperature where water changes from liquid to gas.
2. Recall that standard atmospheric pressure is defined as 1 atm, which is the pressure at sea level.
3. Know that the normal boiling point of pure water at 1 atm is a well-established physical constant, commonly used as a reference point in chemistry.
4. Recognize that the boiling point of pure water at 1 atm is 100 °C, meaning water boils at this temperature under standard atmospheric conditions.
5. Therefore, the temperature at which pure water boils at 1 atm is 100 °C.