I will be happy to critique your thinking on this. First, calculate the moles of H2 used.
2.0e8 L H2/22.4 L H2 = 8.9e6 mol H2
For every 2 mol H2 used -572 kJ of energy is produced
-572 kJ/2 mol H2 = -2.86e2 kJ/mol
I have a balanced equation with this problem. It is:
2 H2 + O2 --> 2 H2O
(where the change in heat is -572 kJ)
I have to discover the heat that is evolved from this equation. Would you have to convert the moles of H2 to kJ of energy using stoichiometry?
I would convert the moles of H2 to kJ by mulitiplying the number of moles of H2 times the heat per mole of H2, which was given in the problem, as I recall.
I would convert the moles of H2 to kJ by mulitiplying the number of moles of H2 times the heat per mole of H2, which was given in the problem, as I recall.
To determine the heat evolved from the given equation, you can use stoichiometry to calculate the heat per mole of H2.
Given:
Moles of H2 used = 8.9e6 mol H2
Heat per 2 mol H2 = -572 kJ
First, calculate the moles of H2O produced using the balanced equation: 2 H2 + O2 -> 2 H2O
Since the ratio is 2 H2 : 2 H2O, the moles of H2O produced will be the same as the moles of H2 used.
Moles of H2O produced = 8.9e6 mol H2
Now, calculate the total heat evolved by multiplying the moles of H2O by the heat per mole of H2.
Heat evolved = Moles of H2O produced * Heat per mole of H2
Heat evolved = 8.9e6 mol H2O * (-2.86e2 kJ/mol)
Calculate the result:
Heat evolved = -2.54e8 kJ
Therefore, the heat evolved from the reaction is -2.54e8 kJ.
Yes, you are correct. In order to find the heat evolved in this reaction, you need to convert the moles of H2 to kJ of energy using stoichiometry. Here's how you can do it:
First, you have determined that 8.9e6 moles of H2 were used in the reaction. Now, you need to use the balanced equation to determine the stoichiometric ratio between H2 and the heat produced.
From the balanced equation: 2 H2 + O2 --> 2 H2O
You know that for every 2 moles of H2 used, -572 kJ of energy is produced. This means that the heat per mole of H2 is -572 kJ/2 = -2.86e2 kJ/mol.
Now, to find the total heat evolved, you can use this conversion factor:
8.9e6 mol H2 * (-2.86e2 kJ/mol) = -2.55e8 kJ
So, the heat evolved from the reaction is -2.55e8 kJ. Note that the negative sign indicates that the reaction is exothermic, meaning heat is released.