- #1
Nelo
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Homework Statement
Several problems.
1) Balance these oxidation-reduction equations in both acidic and basic conditions. In each equation,
underline the oxidizing agent. (I have highlighted them. Remember, the oxidizing agent is the species that
is reduced and gains electrons.)
a)Cr2o7-+ C2H5OH → Cr3+ + CO
b) HNO3 + P -> No + h3po4.
c) C2h4 + MNO4- -> Mn2+ + CO2
Homework Equations
No equations needed
The Attempt at a Solution
I just seem to not understand what the hell is going on. We talked about this breifly but it will be on the exam ( on tuesday) Here is what I got from what she taught...
a) balance all elements except hydrogen and oxygen
b) Balance oxygen using H2o
c) Balance hydrogen using H+
d) balance the charge of rctnt side with charge of product side by adding electrons to either reactant or product
e) Multiply 1 or both balanced half reactions by integer to equalize number of electrons transferred in the two half reactions.
So..#1 in acidic :: Cr2O7-+ C2H5OH → Cr3+ + CO
Cr2O7 ---> Cr3+ First i found charge of Cr in Cr2O7 (which is 6) . since difference of 6 and 3 is 3. and it went from +6 to +3 it gained 3 electrons and was reduced. so the half rctn would be
14H+ + Cr2O7 + 3e ----> Cr3+ + 7H2O
Second half reaction.. : H2C2O4 --> 2 CO2 + 2 H+ + 2 e- ( I don't even understand why that's 2 electrons...?)
Thats basically all i understand .. and that's just the beginning part. Can anyone help me to get to the right steps of this??