## When is K small enough to make the assumption

Odalis Trasvina 1A
Posts: 22
Joined: Fri Sep 25, 2015 3:00 am

### When is K small enough to make the assumption

So i've been hearing different things about when to make the assumption about K and when it is small enough to be disregarded in the quadratic steps of finding equilibrium. Is it when K is 10^-4 and less or 10^-5 and less.

Jonathan Shih 3H
Posts: 37
Joined: Fri Sep 25, 2015 3:00 am

### Re: When is K small enough to make the assumption

Ok, in high school I learned that 10^-4 and greater is ok to make the assumption because when you work the problem out with sig figs, the number itself is enough doesn't have an impact on the final rounded number. However, I asked my TA, Andy Smaligo, just to make sure and he said that for the the problems where the assumption is ok, the number's will be blatantly indicative of whether you can assume or not, an example would be 10^-34 or something along those lines. So, just to be sure, I would still work out the entire calculation for 10^-5 and 10^-5 equilibrium values.
Hope this helps!

Rachel Risoleo 3G
Posts: 19
Joined: Fri Sep 25, 2015 3:00 am

### Re: When is K small enough to make the assumption

I agree with the above. In lecture the other day, Dr. Lavelle said that it is usually okay to make the assumption if K<10^-5, however I would still always check at the end of the calculation to ensure that it did not specifically impact your value!