Calculate Boiling Point Of Water At Different Pressures

Boiling Point Equation:

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

Pressure (P):

Standard Temperature (T₀):

Standard Pressure (P₀):

Enthalpy of Vaporization (ΔHvap):

J/mol

Boiling Point (Tb):

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1. What is the Boiling Point Equation?

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

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

Explanation: The equation shows how boiling temperature changes with pressure, with higher pressures increasing the boiling point and lower pressures decreasing it.

3. Importance of Boiling Point Calculation

Details: Understanding how pressure affects boiling point is crucial in various applications including cooking at high altitudes, industrial processes, chemical engineering, and meteorological studies.

4. Using the Calculator

Tips: Enter pressure in Pascals, standard temperature in Kelvin, standard pressure in Pascals, and enthalpy of vaporization in J/mol. All values must be positive and non-zero.

5. Frequently Asked Questions (FAQ)

Q1: Why does boiling point change with pressure?
A: Boiling occurs when vapor pressure equals atmospheric pressure. At higher altitudes with lower pressure, water boils at lower temperatures.

Q2: What is the standard boiling point of water?
A: At standard atmospheric pressure (101.325 kPa), water boils at 100°C (373.15 K).

Q3: How much does boiling point change with altitude?
A: Roughly 1°C decrease for every 300 meters increase in altitude, though this varies with humidity and other factors.

Q4: Can this equation be used for other liquids?
A: Yes, but you need the appropriate enthalpy of vaporization and standard boiling point for the specific liquid.

Q5: Why use natural logarithm in the equation?
A: The natural logarithm arises from the integration of the Clausius-Clapeyron equation, which describes the relationship between pressure and temperature during phase changes.