Question

The standard free change for reduction of one mole of Feo is

Answer 1

Answer:

ANSWER

Fe+

2

1

O

2

⟶FeO;ΔH=−65kcalmol

−1

. ..(i)

2Fe+

2

3

O

2

⟶Fe

2

O

3

;ΔH=−197kcalmol

−1

...(ii)

By eq, [(ii)−2×(i)]

Also, 2FeO+

2

1

O

2

⟶Fe

2

O

3

;ΔH=−67kcalmol

−1

...(iii)

Let a mole of FeO and b mole of Fe

2

O

3

, are present such that

a+b=1and

b

a

=2

a=

3

2

andb=

3

1

2FeO+

2

1

O

2

⟶Fe

2

O

3

Initial a b

After oxidation (a−2a

′

) b+a

′

Given,

b

a

=2and

b+a

′

a−2a

′

=

2

1

∴

2

a

+a

′

a−2a

′

=

2

1

∴2a−4a

′

=

2

a

+a

′

∴a

′

=

10

3a

=

10×3

3×2

=

5

1

∴FeOused=2a

′

=2/5mol

∵2moleFeOgives67kcal.

∴

5

2

moleFeOgives

2×5

67×2

=13.4kcalheat.

Answer =

6

13.4

≈2