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Tiiba
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A powerful oxidizing agent, a powerful reducing agent. And yet, they form a relatively weak bond. Why?
Dissociation is a property of strong electrolytes in water.Tiiba said:put NaOH in water, you get Na+ and OH-.
What's confusing me is that you keep bringing NaOH into a discussion about the stability of Na2O. It seems to me that you think that because Na2O reacts with water, and possibly also because the products of the reaction are soluble in water, this means that Na2O is unusually unstable, given oxygen's placement on the periodic table (maybe?). Is that the idea you're going for?Tiiba said:Well, obviously, it's not a contact explosive. But when you put NaOH in water, you get Na+ and OH-. Hydrogen is more electronegative than sodium, yet oxygen prefers the company of hydrogen.
Ok. I think if you're basing your conclusions on the links you provided, Borek gave you the best answer: namely, that bond dissociation energies are measured for gas phase species and bear little relation to lattice energies that represent the forces holding ionic solids together. If you're looking at the comparative stability of sodium oxide and (say) sodium iodide, then Bystander gave you the best answer above. Based on the reaction:Tiiba said:I wanted to know why, in general, alkali metals prefer to bond with less electronegative elements like iodine over oxygen. Everybody here seems to think it's an illusion. Maybe it is.
Tiiba said:I wanted to know why, in general, alkali metals prefer to bond with less electronegative elements like iodine over oxygen. Everybody here seems to think it's an illusion. Maybe it is.
Kevin McHugh said:What are you talking about? The halides are the most electronegative elements in the periodic chart.
Borek said:I am not convinced by the data from the table you are right. It lists bond dissociation energy for the NaO dissociation - not for Na2O. While I can imagine NaO being present in gaseous phase at very low pressures, I am not sure its dissociation represents what is going on in Na2O.
Again, you're basing this conclusion on the gas phase stoichiometry. If you look at the crystal structure of solid phase Na2O vs NaCl, you see that a unit cell of NaCl has 4 Na and 4 Cl ions (rock salt structure), whereas sodium oxide has a unit cell with 4 Na and 2 oxygen ions (antifluorite structure). So if you go by the actual unit cell of the species, sodium oxide is more stable ion for ion than sodium chloride. In reality, a better metric for relative stability is the one Bystander pointed out above (which ends up falling pretty much in line with the enthalpies of formation that I mentioned initially).Tiiba said:And I also guess that, despite lower electronegativity, chloride is more stable than oxide because it can form two weak bonds in place of one strong bond.
Tiiba said:does sodium chloride burn in air?
You also have to ask if sodium oxide reacts with chlorine gas (it doesn't). Which implies that the two compounds are roughly equally stable, as the enthalpies of formation tell you.Tiiba said:Wait, does sodium chloride burn in air? Because I don't think it does. For that matter, Wiki says NaI is non-flammable.
Nope, a primitive unit cell of NaCl contains only two atoms, 1 Cl and 1 Na. The cell you have in mind is not primitive.TeethWhitener said:Again, you're basing this conclusion on the gas phase stoichiometry. If you look at the crystal structure of solid phase Na2O vs NaCl, you see that a unit cell of NaCl has 4 Na and 4 Cl ions (rock salt structure), whereas sodium oxide has a unit cell with 4 Na and 2 oxygen ions (antifluorite structure). So if you go by the actual unit cell of the species, sodium oxide is more stable ion for ion than sodium chloride. In reality, a better metric for relative stability is the one Bystander pointed out above (which ends up falling pretty much in line with the enthalpies of formation that I mentioned initially).
I am here with Borek. Have a look at the following site:Borek said:I am not convinced by the data from the table you are right. It lists bond dissociation energy for the NaO dissociation - not for Na2O. While I can imagine NaO being present in gaseous phase at very low pressures, I am not sure its dissociation represents what is going on in Na2O.
DrDu is correct; I was wrong. Thanks for the correction.DrDu said:Nope, a primitive unit cell of NaCl contains only two atoms, 1 Cl and 1 Na. The cell you have in mind is not primitive.
Disodium oxide is considered to be an unstable compound because it has a high reactivity with water, air, and other chemicals. This leads to the compound breaking down and decomposing easily, making it difficult to isolate and study.
The instability of disodium oxide can be attributed to its ionic nature, high energy level, and low lattice energy. These factors make the compound highly reactive and prone to decomposition.
The instability of disodium oxide limits its practical applications as it cannot be used as a standalone compound. It is often used in reactions or as a precursor to other compounds, but it cannot be used in its pure form due to its tendency to decompose.
While disodium oxide is inherently unstable, it can be stabilized to a certain extent by storing it in an inert atmosphere or in a dry, oxygen-free environment. However, it is still a highly reactive compound and difficult to fully stabilize.
The instability of disodium oxide can be beneficial in certain industrial processes where a strong reducing agent is needed. Its high reactivity allows it to easily release oxygen atoms, making it useful in certain chemical reactions. However, this reactivity also makes it difficult to handle and requires caution in its use.