Valhalla Legends Forums Archive | Yoni's Math Forum | Chemical Reaction Balancing

AuthorMessageTime
UserLoser.
On my chemistry homework there's an equation on there that we can do for extra credit -- The teacher said that she never was able to figure it out, but was sure it was possible.. Can anyone here figure it out?

(I hope this is the right one, I'm not exactly sure what number she said it was)

PBr3 + H2O --> HBr + H3PO4
February 29, 2004, 4:41 PM
j0k3r
[quote author=UserLoser. link=board=36;threadid=5512;start=0#msg46710 date=1078072917]
On my chemistry homework there's an equation on there that we can do for extra credit -- The teacher said that she never was able to figure it out, but was sure it was possible.. Can anyone here figure it out?

(I hope this is the right one, I'm not exactly sure what number she said it was)

PBr3 + H2O --> HBr + H3PO4
[/quote]
Maybe I've just forgotten how to do this since I haven't taken it in over a year, but shouldn't there be 3 bromines on the right side of the equation too?

[edit]and only 1 hydrogen on the right, and 1 oxygen?[/edit]
February 29, 2004, 6:18 PM
Adron
PBr3 + H2O --> HBr + H3PO4


x * PBr3 + y * H2O --> a * HBr + b * H3PO4



P: x = b
Br: 3x = a
H: 2y = a + 3b
O: y = 4b

Solution:

Set b = x, a = 3x:
2y = a + 3b = 3x + 3x => y = 3x
y = 4b = 4x => y = 4x

Conclusion:

The equation lacks a solution; the formula is incorrect
February 29, 2004, 6:20 PM
UserLoser.
[quote author=Adron link=board=36;threadid=5512;start=0#msg46723 date=1078078836]
PBr3 + H2O --> HBr + H3PO4


x * PBr3 + y * H2O --> a * HBr + b * H3PO4



P: x = b
Br: 3x = a
H: 2y = a + 3b
O: y = 4b

Solution:

Set b = x, a = 3x:
2y = a + 3b = 3x + 3x => y = 3x
y = 4b = 4x => y = 4x

Conclusion:

The equation lacks a solution; the formula is incorrect

[/quote]

I've never seen an equation done that way :P, but I'll take what you said and go with the formula is incorrect
February 29, 2004, 6:35 PM
SNiFFeR
*I think*
PBr3 + H2O4 --> H2Br3 + H3PO4

P:1
Br:3
H:2
O:4

Something like that, that was like two chapters ago, I was absent for that you just count how many numbers are before the elements.
March 1, 2004, 3:52 PM
j0k3r
[quote author=UserLoser. link=board=36;threadid=5512;start=0#msg46710 date=1078072917]
On my chemistry homework there's an equation on there that we can do for extra credit -- The teacher said that she never was able to figure it out, but was sure it was possible.. Can anyone here figure it out?

(I hope this is the right one, I'm not exactly sure what number she said it was)

PBr3 + H2O --> HBr + H3PO4
[/quote]
Just went over it in class today. This is double displacement.

PBr3 + H2O --> PO + HBr

The metal in the first compound bonds with the non-metal in the second compound and the metal in the second compound bonds with the non-metal in the first...

However, you can try balancing it but Phosphorous and Bromine are both non-metals, hence should not be able to bond... It doesn't look possible.
March 1, 2004, 9:53 PM
K
[quote author=j0k3r link=board=36;threadid=5512;start=0#msg46961 date=1078178003]
[quote author=UserLoser. link=board=36;threadid=5512;start=0#msg46710 date=1078072917]
On my chemistry homework there's an equation on there that we can do for extra credit -- The teacher said that she never was able to figure it out, but was sure it was possible.. Can anyone here figure it out?

(I hope this is the right one, I'm not exactly sure what number she said it was)

PBr3 + H2O --> HBr + H3PO4
[/quote]
Just went over it in class today. This is double displacement.

PBr3 + H2O --> PO + HBr

The metal in the first compound bonds with the non-metal in the second compound and the metal in the second compound bonds with the non-metal in the first...

However, you can try balancing it but Phosphorous and Bromine are both non-metals, hence should not be able to bond... It doesn't look possible.
[/quote]

Non metals can bond via covalent bonding.
March 1, 2004, 10:00 PM
j0k3r
DAMN IT. Well I guess I'll respond again in a couple days if the solution hasn't been found.
March 1, 2004, 10:02 PM
St0rm.iD
You've probably only covered ionic stuff, right?
March 2, 2004, 12:28 AM
j0k3r
Well I suppose that's all she could fit into the day's lesson plan or we would have covered covalent too :o

This chem teacher pushes to learn so much, every day we learn for an hour and 20 minutes and the periods are only an hour and 15 minutes, don't ask how I have yet to figure it out.
March 2, 2004, 1:53 AM
Eibro
If it's a redox reaction (really, i'm too lazy to check) you can balance both half-reactions (adding H3O+/OH- ions to either side) and cancel common terms. At first glance it seems like H2O is the oxidizing agent, and P is the reducing agent. *shrug*
March 2, 2004, 4:17 AM
iago
[quote author=Eibro link=board=36;threadid=5512;start=0#msg47021 date=1078201029]
If it's a redox reaction (really, i'm too lazy to check) you can balance both half-reactions (adding H3O+/OH- ions to either side) and cancel common terms. At first glance it seems like H2O is the oxidizing agent, and P is the reducing agent. *shrug*
[/quote]

*Has horrible memories of AP Chemistry*
March 2, 2004, 2:29 PM
Adron
http://dwb.unl.edu/calculators/activities/BalEqn.html

http://www.unm.edu/~dmclaugh/PrinciplesPDF/11_Equations.pdf

http://mathforum.org/library/drmath/view/64939.html

http://mathforum.org/library/drmath/view/56343.html

April 2, 2005, 12:28 PM
R.a.B.B.i.T
[quote author=iago link=topic=5512.msg47071#msg47071 date=1078237775]
[quote author=Eibro link=board=36;threadid=5512;start=0#msg47021 date=1078201029]
If it's a redox reaction (really, i'm too lazy to check) you can balance both half-reactions (adding H3O+/OH- ions to either side) and cancel common terms. At first glance it seems like H2O is the oxidizing agent, and P is the reducing agent. *shrug*
[/quote]

*Has horrible memories of AP Chemistry*
[/quote]If I remembered chemistry, I'd answer this.  I also dislike the subject.

Anyway, I think the AM has to be equal on both sides?
April 2, 2005, 8:11 PM
Mr. Neo
http://theodoregray.com/PeriodicTable/MSP/BalanceReactions

Error: Reaction can't be balanced.
April 4, 2005, 1:18 AM

Search