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Poly_Gal

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I accidently pressed send 2 times. This is a duplicate request of my previous post. Sorry about that.

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I have finally got the basis of what is going on and how to calculate these types of problems.

My question is how do we come up with the correct formula reaction? I know how to balance a eqtn but predicting the products and other reactants is interesting?

for example I am using the La Grega book on Haz Waste managmet. pg 508 older book, not the latest version.

Eample 9-12 states "Chemcal QTY Determination" problem

I see the nice table for typical oxidation reaction on page 509.

  • I see that we are using a reaction that involves Cl, Na NACN.

But my question here is how did they know what else to add and not use from the reaction that they grabbed on page 509?

If I could just understand this part I would feel so much better.

Could some one please help me understand this simple problem???

Thank you so much!

 
Last edited by a moderator:
I accidently pressed send 2 times. This is a duplicate request of my previous post. Sorry about that.

-----------------------------------------------------------------

I have finally got the basis of what is going on and how to calculate these types of problems.

My question is how do we come up with the correct formula reaction? I know how to balance a eqtn but predicting the products and other reactants is interesting?

for example I am using the La Grega book on Haz Waste managmet. pg 508 older book, not the latest version.

Eample 9-12 states "Chemcal QTY Determination" problem

I see the nice table for typical oxidation reaction on page 509.

  • I see that we are using a reaction that involves Cl, Na NACN.

But my question here is how did they know what else to add and not use from the reaction that they grabbed on page 509?

If I could just understand this part I would feel so much better.

Could some one please help me understand this simple problem???

Thank you so much!

Good question and one I've been struggling with myself. My chemistry background is not that great. You may already know this, but if the equation is specific to a WW question for instance, a lot of the chemical reactions are covered in the texts, like Metcalf and Eddy, they just require some (sometime a lot of) looking.

At this point, I'm hoping that's good enough. Maybe someone else will have something more to add.

 
I don't have a copy of LaGrega (I borrowed a friend's copy for the exam and don't have access to it) so I can't comment directly on your question.

What I can say is that I don't recall ever having to "come up with" a chemical equation on my own. I thought that they either gave you the equation (you might have to balance it) or it is so commonly used in the industry that you would easily be able to find it in a reference (such as Alum addition, chlorine reactions, or other water treatment equations).

If I'm wrong, hopefully someone else will chime in.

 
I think you're right. ^^ I'm not all that strong on chemistry, either (mostly a water/wastewater guy) but I passed...

 
Last edited by a moderator:
I don't have a copy of LaGrega (I borrowed a friend's copy for the exam and don't have access to it) so I can't comment directly on your question.
What I can say is that I don't recall ever having to "come up with" a chemical equation on my own. I thought that they either gave you the equation (you might have to balance it) or it is so commonly used in the industry that you would easily be able to find it in a reference (such as Alum addition, chlorine reactions, or other water treatment equations).

If I'm wrong, hopefully someone else will chime in.
Don't mean to scare anyone, but I think I had to "come up" with the chemical equation for combustion problems.

My advice would be to not overthink it and to save problems with stoichiometery for later. If you feel the problem will be a 15-20 minute one that you would still not be confident about, skip it and go back to it later.

 
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