Simply put, it's a tool chemists use.
An ICE Table (you'll sometimes see this referred to as a RICE Table) is a notation system used to help keep track of how the concentrations of the species involved in an equilibrium rection change during the course of a reaction.
The ICE initials come from
- I - Initial
- C - Change
- E - Equilibrium
This notation system uses the initial concentrations of the species, the way these concentrations change in accordance to their stoichiometric coefficients, and the concentrations you can expect once equilibrium is established.
So, for a generic equilibrium reaction
you start with reactants,
Since the initial concentrations of the products will be zero, the first line of the ICE table will look like this
Now look for how thse concentrations will change once the reaction proceeds. Notice that 1 mole of
Moreover, 1 mole of
This means that, if the concentration of
The second line of the table will be
The final line of the table is simply the sum of the above two lines, i.e. what remains after the change takes place.
You'd then go on to use the respective reaction's equilibrium constant,