00:01
This question deals with stoichiometry.
00:03
And any time we have a stoichiometric question, we also have to start with a balanced reaction.
00:08
So we're told in the question that we have silicon dioxide reacting with hydrofluic acid.
00:14
That's going to produce water in a silicon tetrafluoride product.
00:19
And so first we need to ensure that the left side, all the moles of reactants on the left side, balance properly with the moles of product on the right side of the reaction.
00:30
And they do.
00:31
And so we're starting again with the balanced reaction.
00:36
We're also told in the question that we have 111 liters of hydrofluoric acid that can react.
00:43
And here's the concentration, 0 .32 molar or 0 .032 moles per liter.
00:48
And so we're going to use that balanced reaction at this point to determine how many moles of the silicon tetrafluoride product can be produced from the starting amount first of hydrofluoric acid.
01:04
And the balanced reaction shows us that it requires four moles of hydrofluoric acid to produce one mole of silicon tetrafluoride.
01:12
So let's place that information into all of this information into the balanced reaction.
01:20
And if we crunch the numbers out, we determine that the maximum amount of hydrofluor or silicon tetrafluoride that can be produced by that starting amount of hydrofluoric acid is 0 .89 moles.
01:33
And we're going to do the same thing with the information provided about the other reagent here, the silicon dioxide.
01:40
We're told we have 55 grams of it.
01:42
How many moles is that? let's plug in the molar mass of silicon dioxide.
01:47
It's 60 .09 grams per mole.
01:50
And if we stop the math at this point and looked at our numbers, that would tell us then that we have 0 .92 moles of silicon dioxide available to react in this process.
02:06
And again, just as there is a 4 to 1 molar relationship between the hydrofluoric acid and silicon tetrafluoride, there is a 1 -to -1 relationship...