albertlee Posted October 14, 2004 Share Posted October 14, 2004 In my chemistry, it has listed several compound ions, but it does not explain how they are formed and how their charges are found........ For eg, NH4 with 1 positive charge OH with 1 negative charge SO4 with 2 negative charges HCO3 with 1 negative charge and so on..... How compund ions are formed, and how their charges are found? according to the formula? Maybe possible, tell me what kind of property does the formation of compund ions have thx in advance Albert Link to comment Share on other sites More sharing options...
Skye Posted October 14, 2004 Share Posted October 14, 2004 You can figure out the charge on the compound by the charges (oxidation state) of the atoms that make it up. Example: N3- is bonded to four H+ ions. These add together to give a +1 charge for the compound. Link to comment Share on other sites More sharing options...
5614 Posted October 14, 2004 Share Posted October 14, 2004 heres a good ionic element periodic table, it doesnt show all the elements it doesn't show the +4 ions for tin and lead. notice the two possible charges for hydrogen. really no ions with such high positive charges exist because too much energy is required to strip off 3 or more electrons. http://misterguch.brinkster.net/ionic.html now theres a good site on ionoic compounds, ask if you dont understand any of it! Link to comment Share on other sites More sharing options...
albertlee Posted October 14, 2004 Author Share Posted October 14, 2004 but 5614, I already know much about ionic compounds.... but I want learn more about compound ions. Firstly, I would like to ask, for eg, the compound ions, NH4, what is the bonding between Nitrogen and Hydrogen in this ion? Albert Link to comment Share on other sites More sharing options...
YT2095 Posted October 14, 2004 Share Posted October 14, 2004 http://scifun.chem.wisc.edu/chemweek/Ammonia/AMMONIA.html http://en.wikipedia.org/wiki/Ammonia http://www.chemguide.co.uk/atoms/bonding/hbond.html and... http://www.historyoftheuniverse.com/ammonia.html some of these may help a little more than just me sitting here and trying to typing it all Link to comment Share on other sites More sharing options...
albertlee Posted October 14, 2004 Author Share Posted October 14, 2004 YT, what does hydrogen bonding and ammonia has to do compund ions? I am not familar with hydrogen bonding, it somehow tells that the molecules have charges.....Never know of that, how can molecules have charges? my teacher tells me that compound is neutral for both ionic and molecular....... Any way, confuse... Again, before I go any deeper, I want to know what is the bonding of Nitrogen and Hygrogen in the form of NH4 ion.... Albert Link to comment Share on other sites More sharing options...
Firedragon52 Posted October 14, 2004 Share Posted October 14, 2004 Again, before I go any deeper, I want to know what is the bonding of Nitrogen and Hygrogen in the form of NH4[/sub'] ion.... The Nitrogen and Hydrogens are bonded together through covalent bonding. But, the nitrogen, in this case, has a positive charge because it has four sigma bonds where it only wants three sigma bonds. Does that kinda help a little? Link to comment Share on other sites More sharing options...
Skye Posted October 14, 2004 Share Posted October 14, 2004 On the hydrogen bonding, the electrons in a molecule or compound aren't even distributed. Some areas tend to have more electrons, other less, at any given moment. This gives these areas a weak charge. This charge is much weaker than the charge due to having a missing/extra electron in the case of ions. Hydrogen bonding is simply a matter of 'opposites attract' between hydrogen atoms (which are slightly positively charged), and parts of other molecules or ions that are slightly negatively charged. (edit: you're right there firedragon, don't nkow what my brain is up to) Link to comment Share on other sites More sharing options...
5614 Posted October 14, 2004 Share Posted October 14, 2004 Again, before I go any deeper, I want to know what is the bonding of Nitrogen and Hygrogen in the form of NH4 ion.... YT2095 has already posted a suitable link: http://en.wikipedia.org/wiki/Ammonia Link to comment Share on other sites More sharing options...
albertlee Posted October 14, 2004 Author Share Posted October 14, 2004 but FireDragon, how can Nitrogen in this case take up four sigma bonds? It doesnot make sense... It is like you make up one ion like this H3O which has 1 negative charge.... By the way, what does "sigma" mean? Albert Link to comment Share on other sites More sharing options...
Firedragon52 Posted October 14, 2004 Share Posted October 14, 2004 but FireDragon, how can Nitrogen in this case take up four sigma bonds? It doesnot make sense... It is like you make up one ion like this H3O which has 1 negative charge.... I could be wrong, but I think you're asking why would NH3 and H20 form the less stable ions H30+ and NH4+. This is because of the movement of the electron. Sometimes, it will break away from the nucleus of the H and leave a proton H+. The H+ is attracted to the NH3 and H20 because of the molecules 3D arrangement in space and the molecules partial charge. The Molcules have specific orientations in space. This can be shown using a VSEPR model (http://www.molecules.org/VSEPR_table.html). As you will see in both the... NH3: http://www.molecules.org/Images/animations/NH3.html and the H20: http://www.molecules.org/Images/animations/H2O.html model, that there is a segment of the central atom not being "occupied". That space is the site of a lone pair of electrons. The water molecule's 3D shape causes it to have form a dipole by the unbalanced electronegativity between the H and the O. So a passing proton (H+) gets sucked into the pretty stable water. The same works for NH3. Did I help? By the way, what does "sigma" mean? Just a fancy way of saying "single bond". Double and triple bonds are refered to as PI bonds.http://home.att.net/~cat6a/carb_bonds-I.htm Link to comment Share on other sites More sharing options...
albertlee Posted October 14, 2004 Author Share Posted October 14, 2004 This is because of the movement of the electron. Sometimes' date=' it will break away from the nucleus of the H and leave a proton H+. [/quote'] Firedragon, thx for your explanation, but before understand your post, Can any one explain the above quote more clearly? because my chem teacher say you cant break the electrons from an element, otherwise, in this case it will not be hydrogen any more Secondly, thx Skye for your explanation, now I know more about Hydrogen Bond, but I have also have two questions for this: According to YT's link:http://www.chemguide.co.uk/atoms/bonding/hbond.html, NH3, H2O and HF tend to have more intermolecular force because they obtain higher boiling point than any other molecules with hydrogen bonding, but how do you determine that? what kind of property in Hydrogen bond tells you there is more intermolecular force? For the second question, since there is hydrogen bond, using the same principle, is there oxygen bond, chlorine bond, etc....? thx for any respond Albert Link to comment Share on other sites More sharing options...
5614 Posted October 14, 2004 Share Posted October 14, 2004 "Can any one explain the above quote more clearly?" yes, an electron leaves the H and therefore the H become positively charged (more protons then electrons) so its H+ "because my chem teacher say you cant break the electrons from an element, " that is certainly wrong, when there are more or less electrons that is what an ion is. Link to comment Share on other sites More sharing options...
albertlee Posted October 14, 2004 Author Share Posted October 14, 2004 5614, I know, but why the electron leaves? Link to comment Share on other sites More sharing options...
5614 Posted October 14, 2004 Share Posted October 14, 2004 ack, gotta run, search 'what causes ionisation' on google, i will post here tomorrow, say so if you have the answer though, im sure someone else will answer, till tomorrow (or whenever)! soz Link to comment Share on other sites More sharing options...
albertlee Posted October 14, 2004 Author Share Posted October 14, 2004 There is no ionisation for hydrogen....When an element combines with hydrogen , it is always covalent bonding.... I think FireDragon might mean that share one electron from hydrogen with Nitrogen, then it becomes paritially positive which attracts with lone pair of another NH3 but it does not sound quite right as a formation of a compound ion!!! It is just the intermolecular force that attract every molecule together, and thats all....Nothing much!!! Since NH3 is valent, there is no need to share with another single hydrogen........ So the main question is: How is there an extra hydrogen cobining with NH3 in any way that makes an ion with a complete positive charge? It is kind of complicated, compound ion is bonded with covalent bonding which produces either complete positive or negative charge that is combined with another ion in ionic bonding..... thx for furthur respond Link to comment Share on other sites More sharing options...
budullewraagh Posted October 14, 2004 Share Posted October 14, 2004 the hydrogen forms a coordinate covalent bond Link to comment Share on other sites More sharing options...
albertlee Posted October 15, 2004 Author Share Posted October 15, 2004 the hydrogen forms a coordinate covalent bond budullewraagh, are you answering my question: How is there an extra hydrogen cobining with NH3 in any way that makes an ion with a complete positive charge? ? what do you mean by "coordinate"? besides that, I know hydrogen always form covalent bond, but again, there is no need for NH3 to take up one extra hydrogen to share the electrons....... So again again again, How is there an extra hydrogen cobining with NH3 in any way that makes an ion with a complete positive charge? thx for the responds Albert Link to comment Share on other sites More sharing options...
YT2095 Posted October 15, 2004 Share Posted October 15, 2004 try this then: Weak base + H2O = conjugate acid + OH- Most common weak base is NH3 NH3(aq) + H2O(l) = ? What will K be? Kb K = [NH4+][OH-] / [NH3][H2O] Since water is the solvent, and has a constant concentration Kb = [NH4+][OH-] / [NH3] Kb is the base dissociation constant (like Ka) Kb refers to the equilibrium of the weak base with water to make the conjugate acid and OH- taken from: http://66.102.9.104/search?q=cache:k9DhXTEBwa0J:www.southalabama.edu/chemistry/serafin/ch132/lec14.rtf+%22nh3%22+water&hl=en Link to comment Share on other sites More sharing options...
Primarygun Posted October 15, 2004 Share Posted October 15, 2004 In my chemistry, it has listed several compound ions, but it does not explain how they are formed and how their charges are found........ I think I could help you. I was puzzled in this in my form 3 year. Although I was not taught to learn that, I found it myself:P Polyatomic ion consists of covalent bonds. Just imagine the ammonia molecule, NH3. If it is given one H one , it should be NH4 , right? But it is more stable when it lose one electron . Therefore, it become NH4+. Ya, I nearly forgot to tell you something which was mentioned by my buddies before. They are so professional and this web site are professional too, even is the best of the forums. Sometimes, they may think the thing " coordinate covalent" you have learnt. I am not very powerful so I know the situation you are facing to. Coordinate covalent bond is a covalent bond. Take Ozone,O3 , as example.( please find the structure yourself) One oxygen atom shares one pair to obtain another pair with an oxygen atom. Then the second oxygen atom gives one pair to share with the thrid one, but the third one doesn't give any to share. Coordinate covalent bond occurs. Link to comment Share on other sites More sharing options...
YT2095 Posted October 15, 2004 Share Posted October 15, 2004 good points made break the NH3 down, H+ is a univalent cation. and N- is a trivalent Anion. Link to comment Share on other sites More sharing options...
Primarygun Posted October 15, 2004 Share Posted October 15, 2004 The break produce hydrogen gas? Link to comment Share on other sites More sharing options...
YT2095 Posted October 15, 2004 Share Posted October 15, 2004 well it would yeah, and Nitrogen, but I`m showing How the compound`s formed and Why Link to comment Share on other sites More sharing options...
Primarygun Posted October 15, 2004 Share Posted October 15, 2004 Thank you. Before your clarifying, my mind was that the break gave a ammonia molecule and one hydrogen ion. I was wrong! Is that possible? Only one charged particles stay in room? I think the energy to break to give the hydrogen ion out from that molecule is very large, right? Link to comment Share on other sites More sharing options...
YT2095 Posted October 15, 2004 Share Posted October 15, 2004 it would require alot of energy sure. also rem that Water can act as an acid or a base (amphoteric). and so in the case of the NH3 (a very weak base) the conjugate is shifted, making the OH the Base and the NH4+ the acid. NH3 is Base NH4 is acid Link to comment Share on other sites More sharing options...
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