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Topic: I can't balance this equation...  (Read 14729 times)

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Offline kentucky_girl

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I can't balance this equation...
« on: October 31, 2007, 11:38:08 AM »
Ok, so I'm given that diphosphorus trioxide in mixed with aqueous potassium hydroxide.

And I have to fill in:

_____(s) + ______(aq) ---> _____(aq) + _____(l)

I think that the first two blanks are P2O3 and KOH, and they should produce potassium phosphate and water. But when I looked up the formula for potassium phosphate, I got three different formulas: KH2PO4, K2HPO4, and K3PO4. Help?

Offline AWK

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Re: I can't balance this equation...
« Reply #1 on: October 31, 2007, 11:47:43 AM »
P2O3 forms K2HPO3
AWK

Offline kentucky_girl

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Re: I can't balance this equation...
« Reply #2 on: October 31, 2007, 12:14:48 PM »
P2O3 forms K2HPO3

When I put in P2O3 + 4KOH --> 2K2HPO3 + H2O, it tells me that the 4KOH and the 2K2PHO3 are wrong. What am I doing incorrectly?

Offline AWK

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Re: I can't balance this equation...
« Reply #3 on: October 31, 2007, 12:57:22 PM »
Who or what tells you?
Check all atoms on both sides - they are OK

H3PO3 do not form K3PO3 (it is wrong formula) - only KH2PO3 (limiting reagent KOH) or K2HPO3 (an excess of KOH) are possible
AWK

Offline kentucky_girl

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Re: I can't balance this equation...
« Reply #4 on: October 31, 2007, 01:42:51 PM »
Who or what tells you?
Check all atoms on both sides - they are OK

H3PO3 do not form K3PO3 (it is wrong formula) - only KH2PO3 (limiting reagent KOH) or K2HPO3 (an excess of KOH) are possible

The website we use to submit our homework (webassign.com). It says that the P2O3 and H2O blanks are correct, but not the other two.

Offline Dan

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Re: I can't balance this equation...
« Reply #5 on: October 31, 2007, 06:42:09 PM »
Try taking out spectator ions. The website you're plugging your answer into might be looking for the net ionic equation.
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Offline spaniel53

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Re: I can't balance this equation...
« Reply #6 on: November 02, 2007, 02:41:13 AM »
Hey buddy sorry if this is a little late. But I figured it out:


P2O3 + 6KOH --> 2K3P + 3H2O

I put it in webassign and SCORE!! it works out great. Yeah so hopefully you will be able to see this and type it in before 3:30pm tomorrow. Good Luck!

PS: Don't ask me how i got this or why it ends up this way because i guessed haha.

Offline AWK

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Re: I can't balance this equation...
« Reply #7 on: November 02, 2007, 04:00:18 AM »
Hey buddy sorry if this is a little late. But I figured it out:


P2O3 + 6KOH --> 2K3P + 3H2O

I put it in webassign and SCORE!! it works out great. Yeah so hopefully you will be able to see this and type it in before 3:30pm tomorrow. Good Luck!

PS: Don't ask me how i got this or why it ends up this way because i guessed haha.

From formal point of view (simple algebra) your solution is OK.

But it is crazy stupid solution from chemical point of view. K3P cannot exist in the presence of water! And we talking here about chemistry!
AWK

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