00:02
Hi there.
00:03
In this question, we are trying to determine the theoretical yield in grams of the product here, the iron 3 sulfide.
00:11
So we are trying to find grams of this product.
00:15
We know we are starting with 83 .77 grams of iron and an excess of sulfur.
00:24
All right.
00:25
So this is a mass -to -mass stochometry problem.
00:29
We already have the balanced equation.
00:30
It was given to us.
00:32
So we need to convert from grams of the reactant iron to grams of the product.
00:37
So to do that, we need to go through the mole because we have to use the mole ratio.
00:43
So our first step is going to be to convert from grams of iron to moles of iron.
00:50
We're going to do that by using its molar mass.
00:53
Then we can convert from moles of iron to moles of the fv2s3 by using the mole ratio.
01:02
And the mole ratio comes from the coefficients in that balanced equation.
01:07
So we see that there are 2fe for every 1 f .e .2 .s .3 that's produced.
01:14
Since there's nothing written in front of f .e .2 .s .3, it's understood that it's a 1 for the coefficient.
01:19
So we have a 2 to 1 mole ratio there.
01:23
And then we can convert back to grams of fe2s3 by using its molar mass.
01:29
So it looks like we can solve this in three steps...