Burning 2.00 mol of hydrogen releases 483.6 kJ of energy. Determine how much energy, in kilojoules, must be supplied to convert 5.00 mol of water vapor into hydrogen gas and oxygen gas.

2H2(g) + O2(g) --> 2H2O(g) + 483.6 kJ.

You want to go backwards with 5.00 mols H2O vapor instead of 2.00 mols.
483.6 kJ x (5.00/2.00) = ?

1209

To determine the energy required to convert 5.00 mol of water vapor into hydrogen gas and oxygen gas, we need to use the balanced chemical equation for the reaction. The balanced equation for the conversion of water vapor into hydrogen gas and oxygen gas is:

2H2O(g) -> 2H2(g) + O2(g)

Based on this balanced equation, we can see that for every 2 moles of water vapor (H2O), we obtain 2 moles of hydrogen gas (H2) and 1 mole of oxygen gas (O2).

Now, let's calculate the moles of water vapor in 5.00 mol of water vapor:

moles of H2O = 5.00 mol

Since we have twice as many moles of water vapor as moles of hydrogen gas, the moles of hydrogen gas (H2) will be:

moles of H2 = (moles of H2O) / 2
= 5.00 mol / 2
= 2.50 mol

Similarly, the moles of oxygen gas (O2) will be the same as the moles of hydrogen gas, as they have a 1:1 mole ratio:

moles of O2 = moles of H2 = 2.50 mol

Now, we know that burning 2.00 mol of hydrogen gas releases 483.6 kJ of energy. Since we have 2.50 mol of hydrogen gas, we can calculate the energy required to convert it:

energy required = (moles of H2) * (energy released per mole of H2)
= 2.50 mol * 483.6 kJ / 2.00 mol
= 1210.0 kJ

Therefore, the energy required to convert 5.00 mol of water vapor into hydrogen gas and oxygen gas is 1210.0 kJ.