[illuminatus104]

I'm working problems from a discussion and haven't been able to get the given answer.

The question is - Concentrated nitric acid has a molarity of 15.8 M. What volume of this concentrated acid should be used to prepare 500 mL of a 3.00 M HNO3 solution?

I first figure out how many moles are in the 500 mL solution

500 mL (3.00 mols HNO3/1000 mL) gives me 1.5 mols of HNO3

Now I have to figure out the volume of the 15.8 M concentrate necessary to make a 500 mL solution with a 3.00 M concentration, but I don't know how to do this.

How can I find the volume?

[Borek]

[tex]C = \frac n V[/tex]

You know C, you know n, just solve for V and plug numbers in.

[illuminatus104]

[tex]C = \frac n V[/tex]

You know C, you know n, just solve for V and plug numbers in.

I haven't seen that formula before...what do C and N represent?

[Borek]

I haven't seen that formula before...what do C and N represent?

 

What is the definition of the molar concentration?

[illuminatus104]

I haven't seen that formula before...what do C and N represent?

 

What is the definition of the molar concentration?

Oh, the mols/L of solution. I have it written as M = Mols/Vol. I get .094 L. The answer was 94.6 without a unit (I didn't write it down for whatever reason), must be mL.

Thanks! I keep on forgetting how important that formula is in my solving of these problems.