00:01
Hello.
00:02
Today we'll be talking about chapter 14 question 34, which requires us to make a 0 .5 molar solution of ammonium nh4 -cl, ammonia chloride, and we want to make 2 .5 liters of it.
00:26
And so we need to know how much ammonium chloride we need in grams.
00:30
And so to start, let's just think about what the units of molarity are.
00:41
Malarity, big m, has the units of moles of solute over liters of solution, the volume of the solution.
00:57
And that's the total volume of the solution.
01:00
So if we have 0 .5 molar ammonium chloride, that's the same as having 0 .5 moles of nh4cl, ammonium chloride, say we're making licorice or something, and that's in one liter of solution.
01:19
And so if we just multiply this number by the volume of the solution that we have, we can find how many total moles are in that solution and then get the mass.
01:31
So multiplied by 2 .5 liters.
01:34
Our liters will cancel out, and we'll be left with 1 .25 moles...