FeSO⁴.......Fe²O³+SO²+SO³ define it
Answers
Answer:
Start by identifying the oxidation state for each of the element:
+
2
Fe
+
6
S
−
2
O
4
→
+
3
Fe
2
−
2
O
3
+
+
4
S
−
2
O
2
+
+
6
S
−
2
O
3
−
NOT BALANCED
Only three of the four chemicals-
FeSO
4
,
Fe
2
O
3
, and
SO
2
are directly involved in the redox reaction.
The oxidation state of iron
Fe
has increased from
+
2
in
+
2
Fe
+
6
S
−
2
O
4
to
+
3
in
+
3
Fe
2
−
2
O
3
by one
and therefore
Fe
is oxidized.
The oxidation state of sulfur
S
has declined from
+
6
in
+
2
Fe
+
6
S
−
2
O
4
to
+
4
in
+
4
S
−
2
O
2
by two
and therefore some of the sulfur atoms have been reduced.
The total increases in oxidation numbers shall be the same as the sum of decreases in oxidation numbers in a balanced redox reaction.
The oxidation number increases by
1
for each mole of
Fe
atom oxidized and decreases by
2
for each mole of
S
oxidized.
Therefore for each mole of
S
reduced, two moles of
Fe
atoms shall be oxidized.
Note that sulfur dioxide,
+
4
S
−
2
O
2
, is the only species containing sulfur atoms of oxidation state
+
4
. Thus all of the reduced sulfur atoms would end up in
SO
2
.
The number of moles of sulfur atoms reduced shall therefore equal to the number of
SO
2
molecules produced. This number would be slightly smaller than that of
+
2
Fe
+
6
S
−
2
O
4
given that sulfur atoms that were not reduced got eventually into
+
6
S
−
2
O
3
.
Add coefficients
2
and
1
in front of
FeSO
4
and
SO
2
, respectively:
2
l
+
2
Fe
+
6
S
−
2
O
4
→
+
3
Fe
2
−
2
O
3
+
1
l
+
4
S
−
2
O
2
+
+
6
S
−
2
O
3
−
NOT YET BALANCED
Deduce coefficients for the rest of the species based on the conservation of iron and sulfur atoms.
2
l
+
2
Fe
+
6
S
−
2
O
4
→
1
l
+
3
Fe
2
−
2
O
3
+
1
l
+
4
S
−
2
O
2
+
1
l
+
6
S
−
2
O
3
−
BALANCED
Take coefficients "
1
" out of the expression:
2
l
FeSO
4
→
Fe
2
O
3
+
SO
2
+
SO
3