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gobin

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Everything posted by gobin

  1. I know that when pH is more acidic , you have lots of H+ ions relative to HO- ions. And when water is more basic you have lots of HO- ions over H+ ions. Also just because water is a poor conductor of electricity wouldn't mean that nothing happens in the electrolysis of water.. There'd be some reactions taking place. I think it is valid to talk of the electrolysis of water with pH 7 - neutral water. Even though it's maybe a slow reaction. In theory I suppose the reaction could be sped up even with neutral water, if the H+ ions and HO- ions were increased while maintaining the 50/50 proportion. So maintaining the neutral pH7. But that probably adds another complexity to the question. Also I understand that in chemistry there's no bottle of H+ ions or bottle of OH- ions. People add a salt into it to get more conductivity(which isn't what i'm asking about). And from what I understand , it is valid to speak of the electrolysis of pure water. It's mentioned here https://en.wikipedia.org/wiki/Electrolysis_of_water "Electrolysis of water is using electricity to split water into oxygen (O2) and hydrogen (H2) gas by electrolysis.". Though it's perhaps not often encountered by people.
  2. Hi I understand that in the electrolysis of water, there are these half equations 1. Cathode (reduction): 2 H2O(l) + 2e− → H2(g) + 2 OH−(aq) E=-0.83 2. Anode (oxidation) 2 H2O(l) → O2(g) + 4 H+(aq) + 4e− E=1.23 3. Cathode(reduction) 2H+(aq) + 2e− → H2(g) E=0 4. Anode(oxidation) 4 OH- (aq) → O2(g) + 2H2O(l) + 4e- E=0.4 And from what I understand, all four occur. But two will be the main ones that occur. In Neutral conditions, we'd get (1,2) as the main ones In Acidic conditions we'd get (3,2) as the main ones In Basic conditions we'd get (1,4) as the main ones. And from what I understand, the E values there are SEP - standard electrode potentials, particualrly, E(red), so, for reduction. And they need to be converted into "Actual Potentials" in order to be of any use, is that right? 'cos from what I understand, in order to predict the products that will be the main products, so the half equations that are the main ones. One would look at the half equations for the Cathode, and pick the one with the highest reduction potential. And since E(ox) = E(red)*-1 The half equation with the lowest E(red) value is the one with the highest E(ox), and thus the main one at the Anode. So for the Anode I should pick the lowest E value. But the problem I am having here, is that the E values don't reflect the fact that in neutral conditions I should get (1,2) . In acidic (3,2). And in Basic (1,4). e.g. I get 3. Cathode(reduction) 2H+(aq) + 2e− → H2(g) E=0 <--- Highest E for cathode as 0> -0.83 4. Anode(oxidation) 4 OH- (aq) → O2(g) + 2H2O(l) + 4e- E=0.4 <--- Lowest E for Anode as 0.4 < 1.23 But i'm not sure that any conditions are meant to produce main ones of (3,4). So, i'm thinking the E values would be different for e.g. pH 3 (for acidic), or pH(10) for basic. Let's assume room temperature and atmospheric pressure. I'm wondering what the actual potentials are, and whether that rule about highest E for cathode, and lowest E for Anode, will then apply? Thanks
  3. Note- I am a novice and don't know much and I know you know this but i'm just replying to what you wrote for the benefit of anybody like the poster reading. Ionic bonds are described as intramolecular.. (in the category of covalent bonds and metallic bonds).. If you were to take the word "molecular" in inter/intra molecular, as literal, then everything falls apart because any intramolecular bond is a bond between two molecular units. So I don't think it is to be taken literally like that. I think in the case of the words intermolecular and intramolecular, the term molecular really refers more to "molecule" So then you at least see that Covalent and Metallic are intramolecular, As for ionic, if for example an ionic compound like sodium chloride were boiled up, you'd get some ionic monomers forming, as well as ionic dimers eg.. An atom of Na and an atom of Cl bonded with an ionic bond. That's clearly intramolecular. One area where the definition of ionic bonding as intramolecular is a bit silly is in the case of a big crystal, if we take the idea that a big crystal is not a molecule. i.e. the idea that an "ionic lattice" is not a molecule. But with these particular terms, an "ionic lattice" would/could be thought of as a molecule. One person I spoke to thought that the terms intermolecular and intramolecular don't really apply with an "ionic lattice" 'cos if we understand it as not a molecule, then the terms just don't apply. Anyhow ionic bonds are always (or at least usually) described as intramolecular.. Also the term has to be stretched a bit, because an ion dipole interaction is considered to be intermolecular, A dipole is a type of molecule, but a monatomic ion isn't. So there intermolecular is not between two molecules. So then the term intermolecular gets stretched to include what can be between an atom and a molecule. So intermolecular becomes not necessarily only between molecules, but also between an atom and a molecule. added- and to maybe put a spanner in the works, maybe there is a case that they can be described as intermolecular eg if between two different ionic species https://sites.duke.edu/thepepproject/module-2-drug-testing-a-hair-brained-idea/teacher-notes-chemical-bonds-and-forces/ "Ionic compounds exhibit electrostatic intermolecular forces that form strong bonds with other ionic species." Also I notice this link https://www.reed.edu/chemistry/ROCO/Potential/intermolecular_inter.html; (which i'm looking into) describes ion ion in the same category as ion dipole, as intermolecular.
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