In: Chemistry
Hydrogen gas is blown over hot iron (II) oxide. Write the balanced half reactions and the balanced net ionic equation.
I know the half reactions are
H2 -> H2O and FeO -> Fe
But I don't understand how to get these. Why is the oxygen still with the iron in the half reaction? Thanks.
Note that we must "balance" this reaction
we can't simply get rid of FeO, since it is a solid, therefore
FeO --> Fe
H2 --> H2O
REDOX balancing
First, define the “ACIDIC” solution/conditions as H+ presence and
Basic solution implies OH- once it is balanced.
Also; note that ALL species must be balanced, as well as charges
Typical steps:
1) split half redox cells
2) balance atoms other than O,H
3) balance O by adding H2O
4) balance H by adding H+
5) balance charge by adding e-
6) balance e- by multiplying by the Greatest common divisor
7) Add both equations
8) simplify repeating elements, H+, H2O, and e- typically
9) add OH- if we need basic media, otherwise this is done.
10) Simplify again
FeO --> Fe
H2 --> H2O
balance O adding H2O
FeO --> Fe + H2O
H2O + H2 --> H2O
balance H adding H+
2H+ + FeO --> Fe + H2O
H2O + H2 --> H2O + 2H+
balance charge
2e- + 2H+ + FeO --> Fe + H2O
H2O + H2 --> H2O + 2H+ + 2e-
add all
H2O + H2 + 2e- + 2H+ + FeO --> Fe + H2O + H2O + 2H+ + 2e-
cnacel common terms
H2 + FeO --> Fe + H2O
therefore, this is the balanced reaction
it seems "simple" but in reality, we just ensured balance of: elements, O, H, Fe, and charge/electron balance