Question

2h2+O2-2H2O H=+285.5 what is the enthalpy change in above reaction​

Answer 1

Explanation:

Heat of formation of H2O is -188 kJ/molH 2

+0.5O 2 →H 2 O; ΔH 1

=−188 kJ/mol ....(1)

Heat of formation of H2O2 is 286 kJ/molH 2 +O 2 →H 2O 2

; ΔH 2 =286 kJ/mol ....(2)

Multiply reaction (1) with 2.

2H 2 +O 2→2H 2

O; ΔH 3

=−376 kJ/mol ....(3)

Multiply reaction (2) with 2.

2H 2+2O 2→2H 2O 2

; ΔH 4

=572 kJ/mol ....(4)

(3) - (4)

Subtract equation (4) from the equation (3)

2H 2 O 2 →2H

2 O+O 2

The enthalpy change for the reaction is ΔH

3 −ΔH 4=