1. What is Vapour Density at Equilibrium?

Definition: Equilibrium vapour density is the density of a vapour substance during the stages of reaction at equilibrium.

Purpose: This calculator helps determine the equilibrium vapour density when the number of moles is 2, which is important in chemical equilibrium studies.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( d \) — Equilibrium Vapour Density
• \( D \) — Initial Vapour Density
• \( \alpha \) — Degree of Dissociation

Explanation: The initial vapour density is divided by the sum of the degree of dissociation and 1 to get the equilibrium vapour density.

3. Importance of Equilibrium Vapour Density

Details: Understanding equilibrium vapour density is crucial for studying chemical reactions, particularly in gas-phase reactions where the number of moles changes.

4. Using the Calculator

Tips: Enter the initial vapour density (D) and degree of dissociation (α). The degree of dissociation must be ≥ 0.

5. Frequently Asked Questions (FAQ)

Q1: What is the degree of dissociation?
A: The degree of dissociation is the fraction of solute molecules that dissociate into ions in solution.

Q2: Why is this specific to when number of moles is 2?
A: The formula derivation assumes the reaction involves 2 moles of product from 1 mole of reactant, which is common in many dissociation reactions.

Q3: What units are used for vapour density?
A: Vapour density is typically expressed in g/L or similar density units, relative to a standard (often hydrogen gas).

Q4: How does temperature affect the calculation?
A: Temperature affects both initial vapour density and degree of dissociation, but these should be input as measured/known values at a specific temperature.

Q5: Can this be used for any dissociation reaction?
A: This is specifically for reactions where 1 mole dissociates into 2 moles. Different stoichiometry would require a modified formula.