Gas Stoichiometry Example 1

Jules Bruno
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So here it says, What mass of silver oxide is produced when 384 millimeters of oxygen gas at 736 millimeters of mercury and 25 degrees Celsius is reacted with excess solid silver. Alright, so step one is we need to map out the portion of the story geometric chart you will use. They're giving us within this question the volume of the gas, the pressure of the gas and its temperature. So we know with that information, we can find the moles of our gas because moles equals pressure. Times volume divided by R T for us. We need to convert our pressure into atmospheres. Remember, one atmosphere is 760 tours for 760 millimeters of mercury millimeters of mercury cancel out. And when we do that, we get 0.9684 atmospheres. Then we're going to take the volume which is 0.384 leaders. You're going divide that by the are constant and then remember, you add to 73.15 to get to 98.15 Kelvin from the temperature. This information here what is it doing? Its converting the given quantity that we have These amounts into our moles of given So when I plug all this in my moles of given for oxygen gas comes out to the 0.15199 Moles of oxygen gas Now that we have moles of given we go to step three we do a multi mode comparison to convert moles have given into the moles of are unknown So we're gonna say here moles of oxygen go on the bottom are unknown is what we're being asked to find which is our silver oxide At this point we need to do a mole to mole comparison which says that for every one mole of oxygen gas we have two moles of silver oxide So moles of oxygen gas cancel up and now we have moles of silver oxide. Now step four if necessary Convert the moles of unknown into the final desired units Alright, they're not asking us for moles of silver oxide So I'm just continuing onward So where we get grams of silver oxide? So for every one mole of silver oxide, the mass of two silvers and one oxygen has a combined mass off to 31 0.7 g of silver oxide moles of silver oxide. Cancel out, and now I'll have my final answer of silver oxide. So that comes out to be 7.0 grams off silver oxide. Here are answer has two significant figures because 25 has two significant figures here. We didn't have to do Step five, because from Step five, it says Recall. If you calculate more than one final amount thing, you must compare them to determine that theoretical yield. Here. We're only given amounts for oxygen gas, so Step five isn't necessary. Now, if you don't remember the whole concept of theoretical healed, make sure go back and take a look at my topic. Videos on Theoretical Yield What does it mean? And how does it relate to stoke? Geometry is explained in those series of videos. All right, so now that we've gotten our answer, this is the approach we need to take when it comes to gas store geometry.