00:01
We have our balanced chemical reaction where 6 moles of naoh react with al2o3 and 12 moles of hf to produce 2 moles of cryolite na3alf6 and 9h2o.
00:36
So if we have 200 grams of sodium hydroxide, we can convert that into moles using its molar mass, or one mole, naoh, is 40 grams.
01:04
And then we go from moles sodium hydroxide 6 to moles of cryolite 2.
01:15
Once we have moles of cryolite we can convert that into mass using its molar mass 1 1 mole na3alf6 is 210 grams.
01:41
We then perform a similar calculation with our 200 grams of aluminum oxide.
01:51
We convert it into moles using its molar mass.
01:54
One mole aluminum oxide is 102 grams.
02:04
Then from the stoichiometry we see that one mole aluminum oxide yields two moles of cryolite.
02:18
And then last of all we multiply by the molar mass of cryolite to get grams.
02:28
So one of these is going to produce a smaller amount of cryolite.
02:32
That will be known as the limitine reactant.
02:35
And the amount of cryolite the limitine reactant produces is all we're going to get.
02:41
So if all of the sodium hydroxide react, we get 350 grams cryolite and if all of the aluminum oxide reacts we would get 824 grams cryolite.
03:02
Well we're not going to get the 824 because we're going to run out of our limiting reactant sodium hydroxide.
03:13
Whoops! well that gives you the mass of cryolite but i guess they just want the mass of water...