00:04
And again, calculate the mass in grams of magnesium sulfate heptahydrate that is needed to make 50 milliliters of a 1 .0 molar solution.
00:08
And we're given the molar mass.
00:09
So we're going to start with 0 .100 molar and convert that from molar to moles per liter.
00:12
We're then going to multiply it by our volume, 0 .50 liters.
00:14
Next, we're going to use the molar mass, 1 mole, over 246 .47 grams.
00:17
So let's do some math.
00:18
We have 0 .1 times 0 .050 times 246 .47.
00:21
And that's going to be 1 .23235.
00:23
We have to go through six things, so 1 .23 grams of magnesium sulfate heptahydrate.
00:27
Next, we need to find the mass of sodium carbonate to make a 25 milliliter of 0 .10 molar solution.
00:30
So we're going to do the same thing, moles per liter.
00:32
Multiply that by the volume in liters, 0 .025.
00:34
And then multiply that by the molar mass, 105 .99 over 1 mole.
00:36
So we have 0 .1 times 0 .025 times 105 .99.
00:38
And that's going to be 0 .265 grams of sodium carbonate.
00:43
Number three, same thing, but now we're doing sodium nitrate...