ICE Tables

[LeAirraBullingor2k]

I need some help figuring out how to complete ice tables. How do we know to use -X or X?

[Althea Zhao 1B]

Since the reaction begins with only reactants and moves towards equilibrium as products form, the amount of reactant decreases and the amount of product increases. So, you use +x for products and -x for reactants

[Alfred Barrion 2H]

you use -x typically for the reactants and +x for the products

[JohnWalkiewicz2J]

One way that you can help figure out if the reaction is proceeding forwards (-x from reactants) or backwards (-x from products) is to look at the the Keq (equilibrium constant) if it provides it in the question. If the Keq is < (1.0 x 10^3), then the reaction will proceed forward(-x from reactants, +x to products). If the Keq is larger than (1.0 x 10^3), then the reaction will proceed backwards(+x to reactants, -x from products).

[Jesse Anderson-Ramirez 3I]

It depends on whether the reaction is going forward or reverse. This is found by comparing the reaction quotient (Q) and the chemical equilibrium (K).

[005162520]

Usually +x is used for products and -x is used for reactants, but it does depend if it is a forward or reverse reaction.

[MTanikella_1K]

This depends on each reaction, but if the reaction is moving in the forward direction, reactants in the ice table will have a change of -x and products in the ice table will have a change of +x.

[Leonardo Le Merle 1D]

+ X is generally used for products and - X for reactants, as the former is produced from reaction and the latter is used up. However, I'm sure it depends on the context of the question.

[Ying Yan 1F]

If you are only given intial concentrations of the reactant and products and the K value, then create an equilibrium ratio and solve for Q. If Q < K, then the reaction is moving in the forwrd direction, and the reactants will have -x while the product is +x. On the other hand, if Q > K, then the reaction is moving in the reverse direction and the reactants will be -x and products will be +x. *Note: MOST of the time, the reactants will be -x and the products will be +x. Hope that helps!