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Topic: Another confusing redox reaction [Solve thro. Oxidation number method]  (Read 5158 times)

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Offline aeromat2

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PbSO4 --------> Pb + PbO2 + SO42-

Here, I tried taking account of the net change of the Pb:

Pb: 0 -2 = -2 (for the "Pb")
Pb: 4 -2 = +2 (for the "PbO2")

Now when I got the ratio 2:2, I don't know how to place it within the equation. Can someone help me here?
« Last Edit: January 31, 2011, 06:00:48 PM by aeromat2 »

Offline DevaDevil

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Re: Another confusing redox reaction [Solve thro. Oxidation number method]
« Reply #1 on: January 31, 2011, 05:46:29 PM »
okay, what is the exact question?

do you have to determine the oxidation number? or write the reaction equation?

Offline aeromat2

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Re: Another confusing redox reaction [Solve thro. Oxidation number method]
« Reply #2 on: January 31, 2011, 05:48:24 PM »
okay, what is the exact question?

do you have to determine the oxidation number? or write the reaction equation?

The goal is to determine the balanced equation using the oxidation numbering method. The problem I am having is that I don't know how to use the 2 : 2 ratio that I have obtained.

Offline DevaDevil

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Re: Another confusing redox reaction [Solve thro. Oxidation number method]
« Reply #3 on: January 31, 2011, 05:52:57 PM »
I see 3 Pb-containing compounds and sulfate, but no (unbalanced) reaction equation. Which reaction do you need to balance?

Offline aeromat2

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Re: Another confusing redox reaction [Solve thro. Oxidation number method]
« Reply #4 on: January 31, 2011, 06:01:01 PM »
I'm sorry; I just corrected it now.

Offline DevaDevil

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Re: Another confusing redox reaction [Solve thro. Oxidation number method]
« Reply #5 on: January 31, 2011, 06:09:37 PM »
okay, so, what are the oxidation states of Pb in each of the compounds?

(and I assume you will need water -and protons- to balance the equation?)

Offline aeromat2

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Re: Another confusing redox reaction [Solve thro. Oxidation number method]
« Reply #6 on: January 31, 2011, 06:19:10 PM »
They want us to balance using the method shown here: http://www.saskschools.ca/curr_content/chem30_05/6_redox/redox1_4.htm

Yes, this is an acidic solution.

Offline DevaDevil

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Re: Another confusing redox reaction [Solve thro. Oxidation number method]
« Reply #7 on: January 31, 2011, 06:25:09 PM »
okay

this problem is not too hard because it contains only 1 metal: Pb
The sulfate remains unchanged

your numbers of the oxidation state changes are correct, just write down more clearly that you know Pb starts in the +2 state (and not merely write " 4 -2" )

so knowing this, and knowing that you have to use water and protons to balance the equation, give it a go? (remember you have 2 reactions with Pb going!)

Offline aeromat2

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Re: Another confusing redox reaction [Solve thro. Oxidation number method]
« Reply #8 on: January 31, 2011, 06:35:13 PM »
I know I can proceed but the problem I am having is this; what do I do with the 2:2 ratio? How do I use it to balance the equation? Actually, I know you have to use 2 as the co-efficient for something, but does it depend what I put it on?

Offline AWK

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AWK

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