Pembahasan Ulangan/PAS Kimia XI. Cara Menghitung Tetapan Kesetimbangan Kc (#Short)

Chemical Equilibrium Calculation (Kₑ)
🧪 The problem involves calculating the equilibrium constant ($K_c$) for a reaction occurring in a 2-liter volume.
📊 The initial moles are given: 1.4 mol CO and 1.4 mol H₂, with no product initially formed.
⚖️ At equilibrium, 0.4 mol CH₄ is present, meaning 0.4 mol of reactants were consumed according to stoichiometry.
➗ Concentrations are calculated by dividing moles by the volume (2 liters).

Determining Equilibrium Concentrations
📉 Reactants remaining at equilibrium are calculated by subtracting the consumed amount (0.4 mol) from the initial amount (1.4 mol), resulting in 1.0 mol for both CO and H₂.
➕ Products formed are directly proportional to the moles consumed, with $\text{CH}_4$ forming 0.4 mol.
🔄 The general procedure involves setting up an ICE table (Initial, Change, Equilibrium) using moles (Mula-Mula, Reaksi, Setimbang).

Calculating the Equilibrium Constant ($K_c$)
🧮 The equilibrium constant ($K_c$) is calculated by dividing the product of product concentrations by the product of reactant concentrations, each raised to the power of its stoichiometric coefficient.
📈 Substitute the calculated equilibrium concentrations into the $K_c$ expression.
✅ The final calculated result for the equilibrium constant ($K_c$) is 80.

Key Points & Insights
➡️ Use the formula: $K_c = \frac{[\text{Products}]^{\text{coefficients}}}{[\text{Reactants}]^{\text{coefficients}}}$ at equilibrium.
➡️ Remember to calculate molar concentration ($\text{mol} / \text{Volume in Liters}$) before substituting values into the $K_c$ expression.
➡️ The change in moles at equilibrium is directly proportional to the stoichiometric coefficients of the balanced reaction.

📸 Video summarized with SummaryTube.com on Jan 13, 2026, 04:09 UTC