Elevation in Boiling Point given Vapour Pressure Calculator

Boiling Point Elevation Formula:

\[ \Delta T_b = \frac{(P_o^A - P_A) \times R \times (T_{bp}^2)}{\Delta H_{vap} \times P_o^A} \]

Vapour Pressure of Pure Solvent:

Vapour Pressure in Solution:

Solvent Boiling Point:

Molar Enthalpy of Vaporization:

J/mol

Boiling Point Elevation (K):

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1. What is Boiling Point Elevation?

Definition: Boiling point elevation refers to the increase in the boiling point of a solvent upon the addition of a solute.

Purpose: This calculator helps determine how much a solvent's boiling point increases when a non-volatile solute is added.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ \Delta T_b = \frac{(P_o^A - P_A) \times R \times (T_{bp}^2)}{\Delta H_{vap} \times P_o^A} \]

Where:

\( \Delta T_b \) — Boiling point elevation (Kelvin)
\( P_o^A \) — Vapour pressure of pure solvent (Pascal)
\( P_A \) — Vapour pressure of solvent in solution (Pascal)
\( R \) — Universal gas constant (8.314 J/mol·K)
\( T_{bp} \) — Solvent boiling point (Kelvin)
\( \Delta H_{vap} \) — Molar enthalpy of vaporization (J/mol)

Explanation: The formula relates the change in vapor pressure to the resulting change in boiling point temperature.

3. Importance of Boiling Point Elevation

Details: Understanding boiling point elevation is crucial in chemistry, food processing, and industrial applications where precise temperature control is needed.

4. Using the Calculator

Tips: Enter the vapour pressures in Pascals, boiling point in Kelvin, and enthalpy in J/mol. All values must be positive.

5. Frequently Asked Questions (FAQ)

Q1: Why does boiling point elevation occur?
A: Adding solute decreases the solvent's vapor pressure, requiring higher temperature to reach atmospheric pressure (boiling point).

Q2: What's a typical value for boiling point elevation?
A: For water with common solutes, it's typically 0.5-2°C, but depends on solute concentration.

Q3: Does this work for all solvents?
A: Yes, but the effect is most noticeable with solvents having high \( \Delta H_{vap} \) values.

Q4: How do I find vapour pressure values?
A: Vapour pressure tables or Antoine equation calculations can provide these values.

Q5: What if my solute is volatile?
A: This formula assumes non-volatile solutes. For volatile solutes, more complex calculations are needed.