# Homework Help: [OH-] written in mol

1. Dec 4, 2014

### mimi.janson

1. The problem statement, all variables and given/known data
Hi i need to just check if i have understood this.
The problem statement is that i need to find out what [OH-] is in micromolar/L and nanomolar/L for pH 6

2. Relevant equations
The equation im using is that 10pH-14

3. The attempt at a solution
My attempt was using the pH i was given and putting it in the equation. So i got that 106-14 = 10-8 micromolar/L and 10-8 nanomolar/L

But i am a bit unsure because the way it is questioned is a bit tricky, since i dont think they would let people get away with just changing the writing "micromolar/nanomolar"

So if anyone would please check it out and just tell me if what i did was right or wrong and what is wrong in that case i would be happy

Last edited: Dec 4, 2014
2. Dec 4, 2014

### Staff: Mentor

Where to start...

What does it mean "micromole"? "Nanomole"?

"Molar" typically means concentration measured in mole/L. We don't say molar/L, as the "/L" part is understood to be already there.

3. Dec 4, 2014

### mimi.janson

Ok i meant mmole and nmole. However did i understand it right, the way to solve it?

4. Dec 5, 2014

### Staff: Mentor

Hard to say. The way you wrote it may suggest you have no idea what you are doing, which is why I tried to start at the very beginning.

What is "micromole", what is "nanomole"? Is it possible for a solution to have the same concentration expressed in micromoles/L and nanomoles/L? That's what you wrote in the opening post.

5. Dec 5, 2014

### epenguin

That's not an equation.

If you stated what exactly it is a formula for you might avoid the mistakes you have made.