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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: tomgreenschic on November 05, 2008, 06:33:53 PM

Title: balancing equation
Post by: tomgreenschic on November 05, 2008, 06:33:53 PM

For some reason I just can't balance this one. Thanks :D

_Na₂CO₃+_Na₂S+_SO₂-->_Na₂S₂O₃+_CO₂

Title: Re: balancing equation
Post by: macman104 on November 05, 2008, 07:18:31 PM

I played around with it and got frustrated, so I googled an online balancer (I know Borek has a program also), and it is balanceable.  If you decide to throw in the towel, you can go here:

http://www.webqc.org/balance.php

And enter:

Na2CO3 + Na2S + SO2 = Na2S2O3 + CO2

Title: Re: balancing equation
Post by: Borek on November 06, 2008, 03:29:54 AM

Tricky, but doable. I have converted it ifrst to

Na₂O + Na₂S + SO₂ -> Na₂S₂O₃

(CO₂ can be always added on both sides) but it didn't help much.

Then I realized it is almost balanced - the only problem is, there is too much sodium on the left. Playing with Na₂O and SO₂ I will always need more sulfur (two atoms per thiosulfate). So I decided to try 2Na₂S and the rest was a breeze. But that's more luck than a systematic approach.

Systematic approach will be to use algebraic method (http://www.chembuddy.com/?left=balancing-stoichiometry&right=algebraic-method).

And yes, my EBAS balances this equation in no time.

Title: Re: balancing equation
Post by: AWK on November 06, 2008, 04:45:00 AM

Na₂CO₃ + Na₂S + SO₂ = Na₂S₂O₃ + Na₂S₂O₃ + CO₂

Use oxidation number method - this will give you 2Na₂S + 4SO₂ on the left and 3Na₂S₂O₃ on the right side. Adjusting number od Na₂CO₃ is straighforward.