How much energy must be added to 2 mol H2O (g) to cause it to decompose into H2 and O2?

Question

Gerald Bishop

Chemistry

30 July, 05:47

How much energy must be added to 2 mol H2O (g) to cause it to decompose into H2 and O2?

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Answers (2)

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Kiara · Answer 1

The latent heat of vaporization of water is about 2230 joules per gram so for the 2 moles of H2O it would be the weight of 2 moles in grams x 2230 to get the joules of heat energy to make it vaporize.

Easton Webster · Answer 2

The forward reaction is:

2H₂ (g) + O₂ (g) → 2H₂O (g); ΔH = - 484 kJ

The forward reaction releases 484 kilojoules of energy to form water. As per the reaction equation, in order to cause two moles of water to decompose and make the reaction proceed backwards, 484 kilojoules of energy must be added to water.