Answer:
483.64 kJ
Step-by-step explanation:
The given reaction is:
2H₂(g) + O₂(g) → 2H₂O(g) ΔHrxn = -483.64 kJ
The reaction indicates that 483.64 kJ of energy is released during the formation of 2 moles of H₂O(g). Therefore, to find the energy released during the formation of 1 mole of H₂O(g), we can divide the given value by 2:
Energy released per mole of H₂O(g) = -483.64 kJ / 2
= -241.82 kJ
Hence, 241.82 kJ of energy is released during the formation of 1 mole of H₂O(g).
Now, let's consider the reverse reaction:
2H₂O(g) → 2H₂(g) + O₂(g)
To find the energy that must be added to this reaction, we need to consider the energy change in the reverse direction. Since the given value (-483.64 kJ) represents the energy change in the forward direction, we need to reverse the sign:
Energy change in the reverse direction = -(-483.64 kJ)
= 483.64 kJ
Therefore, 483.64 kJ of energy must be added to the reaction:
2H₂O(g) → 2H₂(g) + O₂(g)