Valhalla Legends Archive

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 from: UserLoser. on February 29, 2004, 10:41 AM
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

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]

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 from: Adron on February 29, 2004, 12:20 PM
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

I've never seen an equation done that way , but I'll take what you said and go with the formula is incorrect

*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.

Quote from: UserLoser. on February 29, 2004, 10:41 AM
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

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 from: j0k3r on March 01, 2004, 03:53 PM

Quote from: UserLoser. on February 29, 2004, 10:41 AM
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

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.

Non metals can bond via covalent bonding.  

DAMN IT. Well I guess I'll respond again in a couple days if the solution hasn't been found.

You've probably only covered ionic stuff, right?

Well I suppose that's all she could fit into the day's lesson plan or we would have covered covalent too  

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.

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 from: Eibro on March 01, 2004, 10:17 PM
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*

*Has horrible memories of AP Chemistry*

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

Quote from: iago on March 02, 2004, 08:29 AM

Quote from: Eibro on March 01, 2004, 10:17 PM
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*

*Has horrible memories of AP Chemistry*

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?

http://theodoregray.com/PeriodicTable/MSP/BalanceReactions

Error: Reaction can't be balanced.