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Redox equations

I need help understanding how to solve redox equations. If you could explain this to me in simple terms I would really appreciate it. i have a sample problem and can't even get past it. The problem is:

K2CrO4 + Mg + HCl to CrCl3 + KCl + MgCl2 + h2O

I need to know how to make a balanced equation out of this. Thank you very much.

Solution Preview

Redox stands for oxidation reduction reaction. This means that some element in the reaction is oxidized while another is reduced in charge.

1) The first thing you want to do is assign oxidation numbers to all elements. Hydrogen is usually always +1 and oxygen is usually always +2. Potassium charge is +1 because it is in column 1 of the periodic table. Cl charge is -1. Knowing these charges we can find the other two unknown metal charges.

You'll find that Cr's charge in K2CrO4 is +6
CrCl3 --> Cr is +3
Mg --> is a solid and thus 0
MgCl2 --. Mg is +2

Therefore Mg is oxidized by +2, and Cr is reduced by -3...going from ...

Solution Summary

This solution is provided in 494 words. It defines redox and provides steps for balancing a redox reaction.

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