1. What is Kp?

Kp is the equilibrium constant calculated from partial pressures of gases in a chemical reaction. It relates to Kc (the equilibrium constant in terms of concentration) through the relationship involving temperature and change in moles of gas.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Kc \) — Equilibrium constant in terms of concentration (dimensionless)
• \( R \) — Gas constant (0.08206 L atm/mol K)
• \( T \) — Temperature in Kelvin (K)
• \( \Delta n \) — Change in moles of gas (products - reactants) (mol)

Explanation: The equation converts between concentration-based (Kc) and pressure-based (Kp) equilibrium constants using the ideal gas law relationship.

3. Importance of Kp Calculation

Details: Kp is essential for gas-phase reactions where partial pressures are more easily measured than concentrations. It helps predict reaction direction and extent under different conditions.

4. Using the Calculator

Tips: Enter Kc (must be positive), temperature in Kelvin, and Δn (can be positive, negative, or zero). The gas constant defaults to 0.08206 L atm/mol K but can be adjusted if needed.

5. Frequently Asked Questions (FAQ)

Q1: When should I use Kp instead of Kc?
A: Use Kp for gas-phase reactions when working with partial pressures. Kc is more appropriate for solutions or when concentrations are known.

Q2: What does Δn represent?
A: Δn is the difference in moles of gaseous products minus moles of gaseous reactants in the balanced equation.

Q3: What if Δn = 0?
A: When Δn = 0, Kp = Kc because (RT)^0 = 1. This occurs when the number of gas moles is the same on both sides of the equation.

Q4: Why must temperature be in Kelvin?
A: The gas constant R is defined using Kelvin, so temperature must be in Kelvin for dimensional consistency.

Q5: Can this be used for non-ideal gases?
A: This formula assumes ideal gas behavior. For real gases at high pressures or low temperatures, corrections may be needed.