Correct Answer:
C. 32°F
The correct answer is 32°F because that is the exact temperature value assigned to the freezing point of water on the traditional Fahrenheit scale.
- Step 2 (Scale Calibration): On the Fahrenheit temperature scale, the freezing point of pure water at standard atmospheric pressure is fixed at exactly 32 degrees, while its boiling point sits at 212 degrees. This splits the difference between freezing and boiling into 180 equal intervals.
- Incorrect Options:
- 0°F is incorrect because 0°F marks the stabilization point of a specialized brine mixture of equal parts ice, water, and salt, which Daniel Fahrenheit used to calibrate his scale baseline.
- 18°F is incorrect because it is an arbitrary temperature value that holds no significant chemical or physical relationship to water.
- 47°F is incorrect because it represents a mild liquid room temperature well above the standard thermal freezing point.