X is to small

[Andrea_Torres]

I read on chemistry community that the x is ignored if the K Is less than 10^-3 but is K always going to be given? If not how will I know when the x should be ignored?

[205007651]

I believe they should always give you K but I'm not completely sure. Also in the review session today, the K was smaller than 10^-3 but we still couldn't discard the x so I'm slightly confused.

[KHowe_1D]

If you didn't have K you wouldn't be able to solve for x. So I think we can assume that we either have to solve for K or for x but not both so in a scenario where you solve for x, K should be given.

[DanielTalebzadehShoushtari2A]

I believe you can check to see if dropping the x is valid. You do the calculation (with x dropped) and then seeing if the resulting concentration value for x is less than 5 percent of the original concentration of solution (what you started with). If it is, then your approximation is valid.

[Sean Tran 2K]

X is dropped when it is less than 10^-3 and the percent at the end is less than 5

[Ryan Chang 1C]

What values do you use to calculate if the percent at the end is less than 5.

[Aarushi Solanki 4F]

You can disregard x when K is less than 10^(-3) because it will be an extremely small value that won't affect your calculations. However, to ensure that you were correct in disregarding the x value, you must check if x is less than 5% of the original solution's concentration.

[Ashley Alvarado 2C]

When Kc< 10^-3 and x is less than 5% of the initial concentration then it is okay to approximate.

[Joanne Lee 1J]

K will always be given when solving for x or else there would be no way for us to find x.