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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: World on December 03, 2009, 09:05:57 PM

Title: Just Making Sure (dor tomorrow's test)
Post by: World on December 03, 2009, 09:05:57 PM

1.) Can someone explain to me how to identify the acid, base, conjugate acid, and conjugate base? My teacher explained it horribly and told me to look in the book, and the book the no help.

2.) Is this how I find the concentration of OH^- ::
:: GIVEN: [H+][OH-] = 1x10^-4
:             H+ = 3.2x10^-4
: OH- = 1x10^-4 / 3.2x10^-4
:^^Divide to get OH-
:
: Or would I just find the pH of 3.2x10^-4 then just subtract from 14 to get OH-?

Title: Re: Just Making Sure (dor tomorrow's test)
Post by: Borek on December 04, 2009, 03:05:45 AM

Both approaches are correct, as they are mathematically equivalent. Take log of the first one and apply pH/pOH definition, and you will see it is the same.

Note: Kw is 10^-14, pay attention to the exponent value.