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Balanced Equation Help

Posted: Wed Sep 26, 2012 4:53 pm
by Ares2009
C6H8 reacts with KMnO4 in cold aqueous KOH to yield MnO2 and C6H12O4. Write the balanced equation using formulas of real compunds....

I'm confused on if this is a hydroxylation reaction or not. I know when an alkene reacts with KmnO4, 2 OH groups form but I'm not sure where to stick them.

So far I have :
C6H8 + 4KMnO4 + 8H20 --> 4MnO2 + 3C6H12O4 + 4KOH

but adding water doesn't follow hydroxylation.

Help please?

Posted: Wed Sep 26, 2012 6:28 pm
by GrahamKemp
Where the hydroxyls go depends on which of the various isomers of C6H8 you used. From the number of O in the product molecule, one of the two cyclohexadiene isomers looks most likely.

Cyclohexa-1,3-diene will produce cyclohexan-1,2,3,4-tetrol
Cyclohexa-1,4-diene will produce cyclohexan-1,2,4,5-tetrol

3 C6H8 + 4 KMnO4 + 8 H2O -(/cold,alkaline)-> 3 C6H8(OH)4 + 4 KOH + 4 MnO2

Structures (using cyclohexa-1,3-diene to produce cyclohexan-1,2,3,4-tetrol)

Structures (using cyclohexa-1,4-diene to produce cyclohexan-1,2,4,5-tetrol)