Water Pressure Boiling Point Calculator

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 at a given pressure. 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)
\( T_0 \) — Standard boiling point (373.15 K)
\( R \) — Gas constant (8.314 J/mol·K)
\( \Delta H_{vap} \) — Enthalpy of vaporization (40650 J/mol)
\( P \) — Pressure (Pa)
\( P_0 \) — Standard pressure (101325 Pa)

Explanation: The equation shows the inverse relationship between pressure and boiling point - as pressure decreases, so does the boiling temperature.

3. Importance of Boiling Point Calculation

Details: Understanding how pressure affects boiling point is crucial in various applications including high-altitude cooking, industrial processes, meteorological studies, and engineering systems involving phase changes.

4. Using the Calculator

Tips: Enter the pressure in Pascals (Pa). The calculator will determine the boiling point of water at that pressure. Pressure must be a positive value.

5. Frequently Asked Questions (FAQ)

Q1: Why does boiling point change with pressure?
A: Boiling occurs when vapor pressure equals atmospheric pressure. At lower pressures, less energy is needed for water molecules to escape, so boiling occurs at lower temperatures.

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

Q3: Can this equation be used for other liquids?
A: The same principle applies, but different liquids have different enthalpy of vaporization values, so the specific coefficients would need to be adjusted.

Q4: How accurate is this calculation?
A: The equation provides a good approximation for pure water under most conditions, though extreme pressures or temperatures may require more complex models.

Q5: What are some practical applications?
A: This calculation is used in food preparation at high altitudes, industrial autoclaves, power plant design, and understanding weather phenomena.