negligible rule [ENDORSED]

[Jasmine Botello 2F]

So when K is small enough, then X can be negligible. Does this apply only to weak acids and bases or any type of reaction?

[Chem_Mod]

This applies to any equilibrium reaction problem that involves an ICE table process to solve. However, you must also consider your initial concentrations or partial pressures. It is actually the % dissociation of an equilibrium reaction being under 5% which allows you to make the negligible x assumption.

[Ethan Vuong 3G]

if we are given an equilibrium constant on a question, is that a good indicator that we are calculating a weak base or acid and therefore eliminate the x?

[Scott Chin_1E]

I think first looking at the reactants and products of the problem would be a good indication for whether the problem is a weak acid/base question, especially if they only give you K instead of or .

If they give you or , I think its safe to assume that you are working with weak acids/bases especially since strong acids do not require equilibrium constants because they dissociate fully.