What is an ICE table and when is it used?
An ICE table tracks Initial concentrations, Changes, and Equilibrium concentrations in chemical reactions. It's used to solve equilibrium problems by organizing data and using the equilibrium constant expression to find unknown concentrations. See also our calculate Mass Balance.
How do I calculate the equilibrium constant?
The equilibrium constant K is calculated using the formula: K = [products]^coefficients / [reactants]^coefficients. For the reaction aA + bB ⇌ cC + dD, K = ([C]^c × [D]^d) / ([A]^a × [B]^b).
What is the reaction quotient (Q) and how does it differ from K?
The reaction quotient Q uses the same formula as K but with current concentrations instead of equilibrium concentrations. Comparing Q to K tells you the reaction direction: Q < K (forward), Q > K (reverse), Q = K (equilibrium).
How do I determine the direction of the reaction?
Compare the reaction quotient Q to the equilibrium constant K. If Q < K, the reaction proceeds forward to reach equilibrium. If Q > K, the reaction proceeds in reverse. If Q = K, the system is already at equilibrium.
What does the x value represent in ICE table calculations?
The x value represents the amount of change in concentration for each species. It's related to stoichiometric coefficients: if coefficient is 2, the change is 2x. Reactants decrease (-x) while products increase (+x).
Can I use this calculator for gas phase reactions?
Yes, select 'Partial Pressures (Kp)' mode for gas phase reactions. The calculation principles are the same, but units change from molarity (M) to pressure (atm), and you'll be working with Kp instead of Kc.