ICE table and X
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ICE table and X
In some circumstances, after using values from the ICE table you eliminate the x in the denominator of the K equation but in other situations you don't. When exactly should or shouldn't you? Is there a cut off value?
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Re: ICE table and X
When the K value is less than 10^-3, it is safe to assume that the value of x will be negligible compared to the initial concentration. However, to make sure that x can be excluded from the denominator in the K expression, you can check that x is less that 5% of the initial concentration.
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Re: ICE table and X
this is correct, it's basically just used to save yourself time not doing the quadratic equation and assuming that a small value being subtracted in the denominator won't really change the equation. because we say it's negligible and not that it's zero, we still keep the x squared in the numerator
Re: ICE table and X
To approximate you would want a K value less that 10^-3, but if you aren't sure whether or not it meets the cut off, then I suggest using the quadratic formula just to be safe.
Re: ICE table and X
You eliminate x from the denominator when K is less than 0.001. This is because when K is this small, the change (x) will be less than 5% of the initial concentration.
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Re: ICE table and X
You can approximate when K is less than 10^-3 because the change in the initial concentration will be so small that x will be a negligible value.
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