if i want to find the molarity of a solution that is:

5mL of a 3.521 x 10^-5 M solution,
and filled to the 50mL line with ethanol,

would this be:

(3.521 x 10^-5)(.04L ethanol)?

3 answers

YOu diluted it by a factor of ten, so it is 1/10 the original molarity.

Molarity=molessolute/litersSOLUTION

So your answer is off.

Molality uses kg solvent in the denominator. Make some flashcards and memorize those.
well, how many moles do you have?
5 *10^-3 L * 3.521 * 10^-5 moles/L
= 17.605 * 10^-8 moles
That is in 50 *10^-3 Liters of solution
so
17.605 *10^-8 moles / 50*10^-3 L
= .3521 *10^-5 moles/L
= 3.521 * 10^-6 M
In other words we diluted it ten to one with ethanol
I mean 9 to one with ethanol.