Consider the reaction: a. If 285.5 mL of SO2 reacts with...

Consider the reaction: a. If 285.5 mL of SO2 reacts with 158.9 mL of O2 (both measured at 315 K and 50.0 mmHg), what is the limiting reactant and the theoretical yield of SO3? b. If 187.2 mL of SO3 is collected (measured at 315 K and 50.0mmHg), what is the percent yield for the reaction?

Consider the reaction:

a. If 285.5 mL of SO2 reacts with 158.9 mL of O2 (both measured at 315 K and 50.0 mmHg), what is the limiting reactant and the theoretical yield of SO3?
b. If 187.2 mL of SO3 is collected (measured at 315 K and 50.0mmHg), what is the percent yield for the reaction?

Transcript

00:01 So this question gives us the reaction 2 s .o .2 gas plus o2 gas gives us 2 s .o .3 gas.

00:17 And we want to find, for part a, we want to find the limiting reactant and theoretical yield.

00:25 And so we can find the limiting reactant by finding the number of moles of each based on the ideal gas law.

00:32 And then compare those number of moles to see which reactant is limiting.

00:39 And so first we'll do so2.

00:43 And so we have the ideal gas law.

00:49 We have our pressure is 50 .0 millimeters of mercury.

00:55 And we can convert that to atmospheres.

00:58 That's 0 .06579 atmospheres.

01:03 That's just dividing the millimeters of mercury by 760, which is the conversion factor.

01:08 We have our volume, which is 285 .5 millimeters, which we want to divide by 1 ,000 to convert into liters.

01:22 Our number of moles is our unknown.

01:25 Our r value is 0 .082057 liter atmospheres per mole kelvin.

01:36 And then our temperature is 315 kelvin.

01:42 And so we rearrange this equation to solve for number of moles n equals pv over r t.

01:49 And we plug in all of these values to get that we have 7 .267 times 10 to the minus 4 moles.

02:00 And so we also need to divide this by 2 in order to compare it to our moles of oxygen since there are 2 moles of s .o2 for every 1 mole of 02.

02:11 And so we'll divide this by two when we compare.

02:16 Now we'll do the same for o2.

02:19 Our pressure is again 0 .06 -579 atmospheres.

02:28 Our volume is now 158 .9 milliliters, which will divide by 1 ,000 to convert to 0 .1589 liters.

02:40 Our number of moles is our unknown.

02:45 Our r value is 0 .082 -057, liter atmospheres per mole kelvin, and our temperature is 315 kelvin.

03:03 So we have that same rearranged ideal gas law equation, n equals pv over rt.

03:09 And when we plug in these values, we get that we have 4 .044 times.

03:16 10 to the minus 4th moles of 02.

03:21 However, since we had to divide our previous answer by 2, we know that, and that when we do divide by 2, it's less than this number of moles.

03:33 We know that our s -o -2 is our limiting reactant...

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