20 cups of flour, 30 eggs, and 10 cups of sugar
Approx.
15
⋅
g
of metal.
Explanation:
Moles of iron oxide,
F
e
2
O
3
=
21.6
⋅
g
159.69
⋅
g
⋅
m
o
l
=
0.135
⋅
m
o
l
with respect to the oxide.
But by the composition of the oxide, there are thus
2
×
0.135
⋅
m
o
l
×
55.8
⋅
g
⋅
m
o
l
−
1
iron metal
=
?
?
g
.
An extraordinary percentage of our budgets goes into rust prevention;
iron(III) oxide
is only part of the redox chemistry. Once you put up a bridge or a skyscraper, which is inevitably steel-based structure, it will begin to corrode.
Answer : The value of
for the reaction is -1131.4 kJ
Explanation :
According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.
The given main reaction is,

The intermediate balanced chemical reaction will be,
(1)

(2)

(3)

Now we will reverse the reaction 1, multiply the reaction 2 by 2, reverse and half the reaction 3 and then adding all the equations, we get :
(1)

(2)

(3)

The expression for
will be,



Therefore, the value of
for the reaction is -1131.4 kJ