negligible rule  [ENDORSED]

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Jasmine Botello 2F
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Joined: Fri Sep 29, 2017 7:04 am

negligible rule

Postby Jasmine Botello 2F » Wed Dec 06, 2017 8:37 am

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?

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Re: negligible rule  [ENDORSED]

Postby Chem_Mod » Wed Dec 06, 2017 8:51 am

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
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Joined: Fri Sep 29, 2017 7:07 am

Re: negligible rule

Postby Ethan Vuong 3G » Thu Dec 07, 2017 3:47 pm

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
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Re: negligible rule

Postby Scott Chin_1E » Thu Dec 07, 2017 3:52 pm

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.

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