00:03
Hi there.
00:04
This question is a dilution problem where you need a certain amount of solution at a specific molarity.
00:13
But all you have available is a solution that is more concentrated.
00:18
So you need to dilute that solution.
00:20
The equation that we use to calculate how much of that stock solution we need is m1 times v1 equals m2 times v2, where m is molarity, v2, the ones represent the concentrated or stock solution, and the twos represent the diluted solution that you're trying to make.
00:42
So we know that our stock solution is 2 .2 molar.
00:46
We are told that in the problem, and we want to calculate what volume of that we would need to make a 0 .50 molar solution, of which we need 50 milliliters.
01:03
Okay, well, to solve for v1, we need to divide a 0 .50 molar solution, of which we need to divide.
01:06
Both sides by 2 .2 molar.
01:14
When we do that, molarity will cancel on the right side and the entire 2 .2 molar will cancel on the left, leaving v1 by itself.
01:23
All right, so we're going to calculate this, and we get 11 .36...