## X Value

Shuyi Yu 1B
Posts: 60
Joined: Fri Sep 28, 2018 12:16 am

### X Value

I know that 10^-5 or lower is when we can disregard the x but if something is 10^-4, can we still disregard and just check that the x value divided by the initial concentration is less than 5%

Tiffany_Cacy_3D
Posts: 70
Joined: Fri Sep 28, 2018 12:24 am

### Re: X Value

I believe this rule is actually anything below 10 to the -3 not -5 so if you had a number to the -4 you should be alright to leave it out. I am not 100% sure that is correct but the 5% rule at the end will always let you know if it was okay to round it a bit.

Ethan Yi 1K
Posts: 62
Joined: Fri Sep 28, 2018 12:28 am

### Re: X Value

yeah. if your estimate is <5% of the original value, then the estimate is ok to use. and the range is 10^-3 to 10^3

Saman Andalib 1H
Posts: 73
Joined: Fri Sep 28, 2018 12:16 am

### Re: X Value

The rule is that if the value of either Ka or Kb is less that 10^-3 so it is fine to disregard x for a value of 10^-4.