joml88 Posted May 13, 2004 Share Posted May 13, 2004 This problem seems really easy (and probably is) but I am troubled by it for some reason. I can't remember it exactly because it was on a test in my high school chem. class today. What is the pH of a solution that has 12.00 g Na(OH)2 and 250.0 mL H2O? Link to comment Share on other sites More sharing options...
joml88 Posted May 14, 2004 Author Share Posted May 14, 2004 Hmm, no one wanted to help. O well I got my test back and I got it right. I asked this question because the pH was about 14.07. While I was taking the test I thought that it was ok to have a pH above 14 but wasn't sure. Link to comment Share on other sites More sharing options...
admiral_ju00 Posted May 15, 2004 Share Posted May 15, 2004 Hmm, no one wanted to help. O well I got my test back and I got it right. I asked this question because the pH was about 14.07. While I was taking the test I thought that it was ok to have a pH above 14 but wasn't sure. or maybe you didn't leave enough time for someone to find this question and answer? Link to comment Share on other sites More sharing options...
joml88 Posted May 15, 2004 Author Share Posted May 15, 2004 Yeah, but this forum is called the homework help forum. Unless it's a project you usually don't have much time for the problems(one day most of the time). I was expecting a reply before I got the test back but since I got the test back first I just told everyone that help wasn't needed anymore. Link to comment Share on other sites More sharing options...
wolfson Posted June 9, 2004 Share Posted June 9, 2004 This problem seems really easy (and probably is) but I am troubled by it for some reason. I can't remember it exactly because it was on a test in my high school chem. class today. What is the pH of a solution that has 12.00 g Na(OH)2 and 250.0 mL H2O? Firstly find out the molarity: Molarity = Number of moles (n) x Volume (dm^3 or L) So: Number of moles = Atomic mass of compound / mass you have therefore n = (22.99 (Na) + 15.99 (O) + 1 (H)) = 39.98g Therefore: n = 12.00 / 39.98 = 0.300 Moles Then molarity Molarity = Number of moles (n) x Volume (dm^3 or L) therefore: M = 0.300 x 0.250 = 0.075 M. Then calculate pH for a base and REMEMBER there are two molecules of OH so: pH(Lx_n) = 0.075 x 2 = 0.15 M (new pH calculative molarity) Thus: pH(base) = Molarity / Water constant (1.0e14) pH(base) = 0.15 / 1.0e14) = 0.0000000000000015 then pH = -Log(final M) pH = -Log(0.0000000000000015 (15e-15) = 14.82 And the pH of an acid or base has an Infinite level. Link to comment Share on other sites More sharing options...
aommaster Posted June 9, 2004 Share Posted June 9, 2004 So, an acid can go below 0? Link to comment Share on other sites More sharing options...
wolfson Posted June 9, 2004 Share Posted June 9, 2004 Yes -2 or even lower they do not have a limit. Link to comment Share on other sites More sharing options...
aommaster Posted June 9, 2004 Share Posted June 9, 2004 oh wow, imagine an acid with -100 as a pH!!! Link to comment Share on other sites More sharing options...
wolfson Posted June 10, 2004 Share Posted June 10, 2004 Dangerous id say, id keep away lol. Link to comment Share on other sites More sharing options...
aommaster Posted June 10, 2004 Share Posted June 10, 2004 Do you really think there is such a thing? It is possible, of course, but what acid has the lowest pH? Link to comment Share on other sites More sharing options...
J'Dona Posted June 10, 2004 Share Posted June 10, 2004 Ouch... a solution with a pH of -100 would be an H+ concentration of 10100 mol dm-3. At that concentration I think the protons would repel each other so much and with so much energy that the solution would explode and probably destroy the Earth with it. Link to comment Share on other sites More sharing options...
aommaster Posted June 10, 2004 Share Posted June 10, 2004 probably destroy the Earth with it I hope that was an exaggeration! Link to comment Share on other sites More sharing options...
J'Dona Posted June 10, 2004 Share Posted June 10, 2004 Not really... I heard somewhere that there's about 1080 fundamental articles in the universe (a googol). Even a cubic micrometer of this solution contains more protons than that, so if you had any significant amount of this solution it ould be quite nasty. Actually, this thing would contain something ridiculously stupid like 1058 protons in one cubic femtometer (about the same distance as between protons in a nucleus), and at that point even the strong nuclear force would be repelling them as well as the electromagnetic. The result would be a very nasty explosion, I do believe, bearing in mind that this amount of protons has about the same mass as the Earth or thereabouts... Link to comment Share on other sites More sharing options...
Crash Posted June 10, 2004 Share Posted June 10, 2004 They can go that low, thoeritically but realistically i dont think they go past -1 (HF) Does anyone know of pH's below this? of an actual acid not just different concentrations of Hydronium Link to comment Share on other sites More sharing options...
aommaster Posted June 11, 2004 Share Posted June 11, 2004 What about alkalis? What is the highest they go up to? I think it is of pH 14 or soemthing, by sodium, lithium and potassium hydroxide or something Link to comment Share on other sites More sharing options...
J'Dona Posted June 11, 2004 Share Posted June 11, 2004 Well... an alkali equivalent to the hyperacid mentioned earlier would hav a pH of about 114, which means that for just about any volume you want to choose (anything that fits into the universe anyway) you get approximately zero H+ ions. Since it only has a pH like that when it contains some water, you'd have to find some way to stop the reversible reaction where H20 becomes H+ and OH- and vice versa, then completely remove all the H2 ions from it. I suppose that water at absolute zero would be like that, as the alkali of water decreases as temperature decreases, but I thought it was theoretically impossible to get something to absolute zero, and you wouldn't be able to do anything with it even if you could. :/ Link to comment Share on other sites More sharing options...
aommaster Posted June 11, 2004 Share Posted June 11, 2004 No, not a hyperacid that would destroy the world Just the strongest alkali that was made? Link to comment Share on other sites More sharing options...
J'Dona Posted June 11, 2004 Share Posted June 11, 2004 I don't know how strong the strongest alkali they've eever made is. An alkali is really just a solution with a very low H+ concentration instead of a very high one, so the principle would be the same except that the species in the solution were accepting protons instead of donating them. So if the solution were the same in principle, the OH- ions would repel and still destroy the Earth. :S I've just tried looking of Google for the strongest alkali, but I can't find anything. :/ There's something about CsOH being the strongest, though I can't confirm that, and I don't know the pH of it anyway... Link to comment Share on other sites More sharing options...
aommaster Posted June 11, 2004 Share Posted June 11, 2004 I tihkn most alkali metals, when reacted with water, form a strong alkali soultion of pH 14 or something. I don't know whether that was a rule or not however Link to comment Share on other sites More sharing options...
wolfson Posted June 13, 2004 Share Posted June 13, 2004 Remember that a pH of any strong acid can go low, HF is a weak acid, HCL with a high molarity can go -2. But the strongest acid on Planet Earth is H(CB11H6Cl6), but HClO4, HCl, H2SO4, and HNO3 are also very strong. Link to comment Share on other sites More sharing options...
YT2095 Posted June 14, 2004 Share Posted June 14, 2004 But the strongest acid on Planet Earth is H(CB11H6Cl6) just out of curiosity, what is it called? Link to comment Share on other sites More sharing options...
aommaster Posted June 14, 2004 Share Posted June 14, 2004 Probably hydro carbo something chloric acid!!!! Link to comment Share on other sites More sharing options...
YT2095 Posted June 14, 2004 Share Posted June 14, 2004 don`t forget the Boron edit: maybe Carborocloric acid? LOL ) Link to comment Share on other sites More sharing options...
aommaster Posted June 14, 2004 Share Posted June 14, 2004 I was wondering what The B was. I forgot it! Link to comment Share on other sites More sharing options...
YT2095 Posted June 14, 2004 Share Posted June 14, 2004 well it may even have a "Hydro" prefix, making it Hydrocarborochloric acid? heheheheheh, and before anyone takes this seriously, we are ONLY GUESSING at names until Wolfson comes back with the answer. there`s no real need for anymore input here unless you KNOW the real answer, otherwise the thread goes down the "Off Topic" pan Link to comment Share on other sites More sharing options...
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