Question

A common stain remover is sold in concentrated form as 3M sodium hypochlorite (NaOCl). You need to create 400 milliliters of a 0.5M solution of sodium hypochlorite to fill a spray bottle. What volume of 3M sodium hypochlorite is needed?

Answer 1

Do you know the formula between Molarity and volume of solution before/after dilution?

Answer 2

Isn't it mole solute over liters in the solution?

Answer 3

That would be the definition of molarity itself. Which is a good thought.
I am thinking about this formula: \( M_1 V_1 = M_2 V_2 \)

Answer 4

oh ok! Now I know what you are talking about. I guess I just don't get where to plug in the numbers into the equation.

Answer 5

So, we need to create "400 milliliters of 0.5 M solution". Our current stock solution is 3 M, but we need to figure out how much to add of this.
If we think of the M1 and V1 to be the initial, we would use the stock solution molarity for M1. We don't know V1 yet. Then M2 V2 is the 0.5 M at 400 mL.

Answer 6

So I am guessing you would just cross multiply the numbers if you already have everything except V1, right?

Answer 7

I don't know if I'd call it cross multiplying (those are all multiplications, no ratios), I think we can just divide M1 from both sides to isolate V1. :)

Answer 8

oh alright, I should have known that. Alright! Thank you for the help! I know what Im doing now :)

Answer 9

Yep, glad to help! :)