At what temperature does water boil at standard atmospheric pressure?

• A. 100~^{m o}C
• B. 50~^{m o}C
• C. 0~^{m o}C
• D. 212~^{m o}C

Answer: (A)

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. At standard atmospheric pressure (1 atm), water boils when its vapor pressure reaches 1 atm.
2. Recall that the standard atmospheric pressure is defined as 1 atm, which is equivalent to 760 mmHg or 101.3 kPa.
3. Know that the commonly accepted boiling point of pure water at 1 atm pressure is 100~^{\circ}C. This is a standard reference point in chemistry.
4. Recognize that the other temperatures listed (50~^{\circ}C, 0~^{\circ}C, 212~^{\circ}C) correspond to different physical phenomena or conditions: 0~^{\circ}C is the freezing point of water, 212~^{\circ}F (not Celsius) is the boiling point in Fahrenheit, and 50~^{\circ}C is below boiling under standard pressure.
5. Therefore, conclude that water boils at 100~^{\circ}C under standard atmospheric pressure.