Question

What is the pH of a solution that has a concentration of hydronium ions that is 4.7 × 10-4 M OH-? Show, or explain, the work used to solve this problem.
Please help ASAP, I don't know how to do it.

Answer 1

Do you remember
pH+pOH=14

Answer 2

We can find pOH directly by using
\[pOH=-\log[OH^-]\]

Answer 3

What do you get for pOH?

Answer 4

sorry I was away a little while
and I was sick this entire week so im way behind so I have no idea how to solve it (and to make it worse i left my text book at school.....)

Answer 5

I do recall that equation though but i don't know what the variables are representing

Answer 6

Ok, the equations to find pH and pOH from given [concentration] are
\[pH=-\log[H^+]\]
and
\[pOH=-\log[OH^-]\]
-------------------------------------------------
\([H^+]=\text{Concentration of hydronium/proton ion}\)
\([OH^-]=\text{Concentration of hydroxide ion}\)
-------------------------------------------------
Given the concentration of hydroxide ions 4.7 × 10-4 M OH- we can use
\[pOH=-\log[OH^-]\]
\[pOH=-\log[4.7 × 10^{-4}]\]
Then pOH you get is 3.328

Answer 7

so the answer is 3.328 right? thank you very much!

Answer 8

No that is not

Answer 9

You have to use pH+pOH=14 to find pH

Answer 10

...offline

Answer 11

wait....i'm confused again (please remember I have not learned this).....
so now that I know pOH is 3.328 it becomes
pH+3.328=14
ph=14-3.328= 10.672?
(oh and internet connections are bad here so i went offline for a little)

Answer 12

Yes that's correct, pH is 10.672

Answer 13

thank you again