6th edition, 14.17

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Hai-Lin Yeh 1J
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6th edition, 14.17

Postby Hai-Lin Yeh 1J » Thu Feb 28, 2019 7:08 am

(a) Write balanced half-reactions for the redox reaction of an acidified solution of potassium permanganate and iron(II) chloride.

How would we start off this question? I'm not sure where they got Fe2+ -> Fe3+ from and MnO4- -> Mn2+

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Re: 6th edition, 14.17

Postby Chem_Mod » Thu Feb 28, 2019 6:12 pm

The best way to tackle these kinds of problems is to practice. When a half reaction contains permanganate, it's always going to have a redox pair between MnO4- and Mn2+. Same thing with iron, as the redox pair is usually between an Fe2+ and an Fe3+. Whenever you want to balance oxygens, we usually add H2O, and then add H+ to balance the hydrogens from that added H2O, after which we balance charge with addition of electrons.

annabel 2A
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Re: 6th edition, 14.17

Postby annabel 2A » Sun Mar 10, 2019 2:12 pm

Why is it Fe2+ --> Fe3+ and not Fe2+ --> Fe or any of the other ones? Should we just assume that it will be Fe2+ --> Fe3+?

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