Use data from Appendix IIB to calculate the equilibrium constants at 25 °C for each reaction. b. 2 H₂S(g) ⇌ 2 H₂(g) + S₂(g)

Verified step by step guidance

1. Identify the reaction for which you need to calculate the equilibrium constant: \(2 \text{H}_2\text{S}(g) \rightleftharpoons 2 \text{H}_2(g) + \text{S}_2(g)\).
2. Use the standard Gibbs free energy change (\(\Delta G^\circ\)) values from Appendix IIB for each species involved in the reaction to calculate \(\Delta G^\circ_{\text{reaction}}\).
3. Apply the formula \(\Delta G^\circ = -RT \ln K\) to relate \(\Delta G^\circ\) to the equilibrium constant \(K\), where \(R\) is the universal gas constant (8.314 J/mol·K) and \(T\) is the temperature in Kelvin (298 K for 25 °C).
4. Rearrange the formula to solve for \(K\): \(K = e^{-\Delta G^\circ / RT}\).
5. Substitute the calculated \(\Delta G^\circ\) and the values of \(R\) and \(T\) into the equation to find the equilibrium constant \(K\).

Key Concepts

Equilibrium Constant (K)

The equilibrium constant (K) is a numerical value that expresses the ratio of the concentrations of products to reactants at equilibrium for a given chemical reaction at a specific temperature. It provides insight into the extent of a reaction; a large K indicates that products are favored, while a small K suggests that reactants are favored. The equilibrium constant is temperature-dependent and is calculated using the formula K = [products]^[coefficients] / [reactants]^[coefficients].

Le Chatelier's Principle

Le Chatelier's Principle states that if a dynamic equilibrium is disturbed by changing the conditions, the system will adjust itself to counteract the change and restore a new equilibrium. This principle helps predict how changes in concentration, pressure, or temperature will affect the position of equilibrium in a reaction. Understanding this concept is crucial for interpreting how shifts in conditions can influence the equilibrium constant.

Standard Conditions

Standard conditions refer to a set of specific conditions (usually 1 atm pressure and 25 °C) under which thermodynamic measurements are made. These conditions provide a reference point for calculating equilibrium constants and other thermodynamic properties. When calculating equilibrium constants, it is essential to ensure that the data used corresponds to these standard conditions to ensure accuracy and consistency in results.