[kerby99]

Does anybody know how to solve this kind of question?

What is the percent yield of a reaction in which 288 g phosphorus trichloride reacts with excess water to form 105 g HCl and aqueous phosphorus acid (H3PO3)?

[achibaby1974]

What is the percent yield of a reaction in which 288 g phosphorus trichloride reacts with excess water to form 105 g HCl and aqueous phosphorus acid (H3PO3)?

ok. I'm gonna try this one. I had this same one on WEBASSIGN!!!

PY is what?

Percent yield is Actual Yield/Theoretical Yield x 100% right?

The ACTUAL YIELD is already given to you. It is 129 g HCl. If you put actually in the statement it works! . a reaction in which 288 g phosphorus trichloride reacts with excess water to (ACTUALLY) form 105 g HCl.. see? it works!)   

So, What is the equation first?

PCl3 + H2O ---------> HCl and H3PO3 (unbalanced)

1PCl3 + 3H20 --------> 3HCl + 1H3PO3 (aq)

So, first we have to do the limiting reactant thing. (LR for short)

If PCl3 is LR then...

216g PCl3 (1mol / 137.32 g PCl3) (3 mol HCl/1 mol PCl3) (36.458 g HCl / 1 mol HCl) = 172.0418293 g HCl 

well, now we can't really limit water b/c there ain't nothin to limit by. The problem just says excess water.

So we have to conclude that 172.0418293 g HCl is our THEORETICAL YIELD. We already got our Actual yield remember? It's the given 129 g HCl. SO now, you plug into the formula. FUN!!!!


PY = (AY/TY) X 100% = (129/172.0418293) x 100% = 74.98176491 ---- don't forget correct sig fig..

That would make it 75.0%!!!!!!!!!

Hope it makes sense. Good luck

[DrCMS]

What is the percent yield of a reaction in which 288 g phosphorus trichloride reacts with excess water to form 105 g HCl and aqueous phosphorus acid (H3PO3)?

ok. I'm gonna try this one. I had this same one on WEBASSIGN!!!

PY is what?

Percent yield is Actual Yield/Theoretical Yield x 100% right?

The ACTUAL YIELD is already given to you. It is 129 g HCl. If you put actually in the statement it works! . a reaction in which 288 g phosphorus trichloride reacts with excess water to (ACTUALLY) form 105 g HCl.. see? it works!)   

So, What is the equation first?

PCl3 + H2O ---------> HCl and H3PO3 (unbalanced)

1PCl3 + 3H20 --------> 3HCl + 1H3PO3 (aq)

So, first we have to do the limiting reactant thing. (LR for short)

If PCl3 is LR then...

216g PCl3 (1mol / 137.32 g PCl3) (3 mol HCl/1 mol PCl3) (36.458 g HCl / 1 mol HCl) = 172.0418293 g HCl 

well, now we can't really limit water b/c there ain't nothin to limit by. The problem just says excess water.

So we have to conclude that 172.0418293 g HCl is our THEORETICAL YIELD. We already got our Actual yield remember? It's the given 129 g HCl. SO now, you plug into the formula. FUN!!!!


PY = (AY/TY) X 100% = (129/172.0418293) x 100% = 74.98176491 ---- don't forget correct sig fig..

That would make it 75.0%!!!!!!!!!

Hope it makes sense. Good luck

Did you use different weights from those detailed in the question for any particular reason?

[achibaby1974]

OMG!!! I'm sooo sorry we had the same substances but not the same #'s. I'm retarded. okay. MY PROBLEM was:

What is the Percent Yield of a reaction in which 216 g of phosphorus trichloride reacts with excess water to form 129 g HCl and aqueous phosphorous acid (H3PO3).

Now my answer should make sense..

PY is what?

Percent yield is Actual Yield/Theoretical Yield x 100% right?

The ACTUAL YIELD is already given to you. It is 129 g HCl. If you put actually in the statement it works! . a reaction in which 288 g phosphorus trichloride reacts with excess water to (ACTUALLY) form 105 g HCl.. see? it works!)   

So, What is the equation first?

PCl3 + H2O ---------> HCl and H3PO3 (unbalanced)

1PCl3 + 3H20 --------> 3HCl + 1H3PO3 (aq)

So, first we have to do the limiting reactant thing. (LR for short)

If PCl3 is LR then...

216g PCl3 (1mol / 137.32 g PCl3) (3 mol HCl/1 mol PCl3) (36.458 g HCl / 1 mol HCl) = 172.0418293 g HCl 

well, now we can't really limit water b/c there ain't nothin to limit by. The problem just says excess water.

So we have to conclude that 172.0418293 g HCl is our THEORETICAL YIELD. We already got our Actual yield remember? It's the given 129 g HCl. SO now, you plug into the formula. FUN!!!!


PY = (AY/TY) X 100% = (129/172.0418293) x 100% = 74.98176491 ---- don't forget correct sig fig..

That would make it 75.0%!!!!!!!!!

Hope it makes sense. Good luck