00:02
Hello, this question is a dilution problem because we're starting with a certain amount of a solution of a specific molarity, and we're adding more solvent to that amount to produce a solution that is less concentrated than the original one.
00:24
So we have an equation that we can use anytime we have a dilution problem, and that is m1 times v1 equals m2 times v2, where m represents molarity, v represents the volume, the 1s represent the initial conditions, and the 2s represent the new conditions.
00:42
All right, so we have a solution that has a molarity of 0 .38, and we're starting with 12 milliliters of that solution.
00:57
We want to know the new concentration if we add 7 milliliters to that original 12.
01:03
So we have 12 milliliters, we add 7 .0 milliliters, keeping significant figures in mind, this would just be 19 milliliters, because we round to the position of the uncertain digit in the least precise measurement.
01:20
So 12 is the least precise, the 2 is in the uncertain digit position, because it's always the last digit, and so we need to round to the 1s place, giving us 19 total milliliters of solution now.
01:32
Since we started with 12 and we added 7...