What quantity of dihydrogen and dioxygen gas will result if a #6.2*mol# of water is decomposed?

Question

Cameron Andrews · Accepted Answer

Well, you need a stoichiometric equation to represent the decomposition of water..........

And here is one such: #H_2O(l) rarr H_2(g) + 1/2O_2(g)# Is this stoichiometrically balanced? If it is not, then we cannot accept this as a true representation of physical reality. This is in fact a redox equation, because while the oxygen in water is formally oxidized to oxygen gas, the hydrogen in water is formally reduced to dihydrogen gas. And clearly, we would expect this process to be quite endothermic. Why so? So you have #6.2*mol# of water to decompose........The stoichiometry quite clearly dictates that #6.2*mol# of dihydrogen gas will result, along with #3.1*mol# of dioxygen gas. Are you with me? And if the gases are measured under the same conditions of temperature and pressure (and we would anticipate such measurement!), we could also specify that #"TWO VOLUMES"# of dihydrogen are evolved for #"EACH VOLUME"# of dioxygen gas.

Luna Chen · Answer

undefined When water (H2O) is decomposed, it yields twice as many moles of hydrogen gas (H2) as moles of oxygen gas (O2). Therefore, if 6.2 moles of water is decomposed, it will produce 12.4 moles of hydrogen gas and 6.2 moles of oxygen gas.