Water Boiling Calculator Pressure

Boiling Point Equation:

\[ T_b = \frac{1}{\frac{1}{T_0} - \frac{R}{\Delta H_{vap}} \ln \left( \frac{P}{P_0} \right)} \]

Boiling Point (T_b):

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1. What is the Water Boiling Point Equation?

The boiling point equation calculates the temperature at which water boils under different pressure conditions. It's based on the Clausius-Clapeyron relation and accounts for how pressure affects the boiling temperature of water.

2. How Does the Calculator Work?

The calculator uses the boiling point equation:

\[ T_b = \frac{1}{\frac{1}{T_0} - \frac{R}{\Delta H_{vap}} \ln \left( \frac{P}{P_0} \right)} \]

Where:

\( T_b \) — Boiling point (K)
\( T_0 \) — 373.15 K (standard boiling point at sea level)
\( R \) — 8.314 J/mol·K (gas constant)
\( \Delta H_{vap} \) — 40650 J/mol (enthalpy of vaporization)
\( P \) — Pressure (Pa)
\( P_0 \) — 101325 Pa (standard atmospheric pressure)

Explanation: The equation shows how boiling temperature decreases with decreasing pressure and increases with increasing pressure.

3. Importance of Boiling Point Calculation

Details: Understanding how pressure affects boiling point is crucial for various applications including high-altitude cooking, industrial processes, meteorological studies, and scientific research.

4. Using the Calculator

Tips: Enter pressure in Pascals (Pa). The calculator will compute the corresponding boiling point of water in Kelvin. Pressure must be greater than 0.

5. Frequently Asked Questions (FAQ)

Q1: Why does boiling point change with pressure?
A: Boiling occurs when vapor pressure equals atmospheric pressure. Lower pressure means water molecules need less energy to escape, so boiling occurs at lower temperatures.

Q2: What is the boiling point at high altitudes?
A: At higher altitudes where pressure is lower, water boils at temperatures below 100°C. For example, at 3000m altitude, water boils at about 90°C.

Q3: How accurate is this equation?
A: The equation provides a good approximation for most practical purposes, though very precise measurements may require more complex equations accounting for additional factors.

Q4: Can this be used for other liquids?
A: The same principle applies, but different liquids have different enthalpy of vaporization values and would require adjustment of the constants.

Q5: What are typical pressure values?
A: Sea level: ~101325 Pa, 1000m altitude: ~90000 Pa, 3000m altitude: ~70000 Pa, pressure cookers: 130000-200000 Pa.