00:01
So for this problem, we want to find the percent purity of fe03 in some sample, given some reaction that occurs in a blast furnace.
00:10
And so we know that 1 .64 times 10 to 3 kilograms of iron are obtained from a 2 .62 times 10 to 3 kilogram sample of fe203.
00:26
So this quantity will have some other things other than fe203.
00:30
We want to find how much of that is actually within the sample.
00:34
So the first thing that we want to do is we want to actually find the molar mass of fe2 -03, so we can do some basic dimensional calculations with this.
00:44
So you have two iron atoms, each of which are 55 .85.
00:52
And then we have three oxygen atoms, each of which are 16 .0.
00:58
And so when we multiply that through, we will get that the molar mass that we are dealing with, is 159 .70 grams per mole.
01:13
So the next thing that we want to do is you want to convert kilograms of fe into kilograms of fe 203 to find how much of that sample is actually pure and how much fe203 it actually contains.
01:27
So we're going to start with 1 .64 times 10 to 3 kilograms of fe.
01:34
So you want to convert this into grams.
01:40
And now we want to divide by the molar mass, the atomic mass of iron, so that we can get moles of iron and then do some dimensional analysis.
01:50
So we know that that is 55 .85 grams per one mole of iron...