Question

The diagram illustrates the energy change of a set of
reactions.
AH = -134 kJ mol-1
P
AH = +92 kJ mol-1
R.
AH = -75 kJ mol-1
Which of the following statement are correct?​

Answer 1

Answer:

Solution:- (C) −394+(−286×2)−(−726)

C

(s)

+O

2

(g)

→CO

2

(g)

;ΔH

c

=−394kJmol

−1

.....(1)

H

2

(g)

+

2

1

O

2

(g)

→H

2

O

(l)

;ΔH

c

=−286kJmol

−1

2×[H

2

(g)

+

2

1

O

2

(g)

→H

2

O

(l)

;ΔH

c

=−286kJmol

−1

]

2H

2

(g)

+O

2

(g)

→2H

2

O

(l)

;ΔH

c

=−572kJmol

−1

.....(2)

CH

3

OH

(l)

+

2

3

O

2

(g)

→CO

2

(g)

+2H

2

O

(l)

;ΔH

c

=−726kJmol

−1

CO

2

(g)

+2H

2

O

(l)

→CH

3

OH

(l)

+

2

3

O

2

(g)

;ΔH

c

=726kJmol

−1

.....(3)

Adding equation (1),(2)&(3), we get

C

(s)

+2H

2

(g)

+

2

1

O

2

(g)

→CH

3

OH

(l)

;ΔH

c

=−394+(−286×2)−(−726)