Calculating Equilibrium Concentrations for a Chemical Reaction
Overview of the Calculation Process
When dealing with chemical equilibrium involving multiple gases, it is essential to consider the equilibrium constants and reaction stoichiometry to determine the equilibrium concentrations of each gas. In this case, the reaction H2(g) + I2(g) â 2HI(g) has an equilibrium constant of Kc = 54.3 at 430°C. To calculate the equilibrium concentrations of H_2, I_2, and HI, an iterative approach based on reaction stoichiometry and equilibrium constants is used.
Step-by-step Calculation
1. Define Initial Concentrations and Equilibrium Constant:Initial concentration of H_2 (H_2_initial): 0.595 M
Initial concentration of I_2 (I_2_initial): 0.375 M
Initial concentration of HI (HI_initial): 0.854 M
Equilibrium constant (Kc): 54.3
An array is used to track the change in concentration for each gas as the reaction reaches equilibrium. Initialize a 3-element array (change) with zeros.
3. Define Reaction Stoichiometry:The stoichiometry of the reaction determines how the concentrations of the reactants and products change. The stoichiometry for this reaction is:H2: -1, I2: -1, HI: 2.
4. Iterate Until Equilibrium:Use an iterative approach to find the equilibrium concentrations by calculating the reaction quotient (Q) and comparing it with the equilibrium constant (Kc) to determine if equilibrium is reached. Update the concentrations iteratively until equilibrium is achieved.
5. Calculate Equilibrium Concentrations:Once equilibrium is reached, the updated concentrations of H_2, I_2, and HI represent the equilibrium concentrations. In this case, the equilibrium concentrations are:H_2: 0.3297 M, I_2: 0.1099 M, HI: 1.4028 M.