QuarkQuarkQuark2001 Posted May 30, 2004 Posted May 30, 2004 1.Why the chemical formula of an ionic compound shows [the types of ions present and the ratio of one type ion to other ]differently from the chemical formula of covalent compound ( molecule )shows [acutal number of atoms of element]?? 2.Why aren't ionic compound not molecules? Seek for your helps
Bryn Posted May 30, 2004 Posted May 30, 2004 In an ionic solid all the atoms are bonded to all the atoms around it. This is true thorught the entire solid, so in effect everything is bonded together. If you used to number of actual atoms in the chemical formula you'd be using rather large numbers in the billions, which would make the formula rather long winded. Using ratios just makes things so much simplier. If you need to know how big the solid is you can say it has blah blah number of moles in it, which is a far easier way of doing things. as for the second question, the term molecule is used rather loosly for ionic compounds. When describing the type of solid you can have giant ionic, giant molecule, as well as ionic and molecule, which means different things. But you can use the term "a molecule of sodium chloride" sodium chloride being an ionic solid. So i'd use the term molecule in relation to ionic compounds loosly, it can sorta apply but it can also sorta not apply, if you see what i mean (which may be difficult )
QuarkQuarkQuark2001 Posted May 31, 2004 Author Posted May 31, 2004 In an ionic solid all the atoms are bonded to all the atoms around it. This is true thorught the entire solid' date=' so in effect everything is bonded together. If you used to number of actual atoms in the chemical formula you'd be using rather large numbers in the billions, which would make the formula rather long winded. Using ratios just makes things so much simplier. If you need to know how big the solid is you can say it has blah blah number of moles in it, which is a far easier way of doing things. as for the second question, the term molecule is used rather loosly for ionic compounds. When describing the type of solid you can have giant ionic, giant molecule, as well as ionic and molecule, which means different things. But you can use the term "a molecule of sodium chloride" sodium chloride being an ionic solid. So i'd use the term molecule in relation to ionic compounds loosly, it can sorta apply but it can also sorta not apply, if you see what i mean (which may be difficult )[/quote'] Thanks
QuarkQuarkQuark2001 Posted June 1, 2004 Author Posted June 1, 2004 NaCl = continuos although it is just stated to be NaCl Does molecule share ? Oh may be I know, in ionic bond the ions share with ions totally , but molecule keep together close only by electrostatic forces and don't react(combine).Am I right?
Tian_07 Posted June 1, 2004 Posted June 1, 2004 Ionic Compounds are made by electronic attraction, and, therefore, break back into the original ions (Na+ and Cl- for Sodium Chloride) when dissolved into water or amphiprotic solvent. All acids and Bases work on this principle. Covalent Molecules are actually individual molecules, and are bonded by their valance electorn configuration. Ionic Compounds are different in the sense that they are... yeah... just ratios... but covalent molecules are actually individuals. How does one actually differentiate an ionic from covalent using only the name? Is there a proper way... or is it memorization of formulas. I know about ions and stuff... but not too much... anyone got anythin on this? Cheerz
aommaster Posted June 1, 2004 Posted June 1, 2004 How does one actually differentiate an ionic from covalent using only the name? what do you mean by using only the name. Something like "iron oxide"? The name of the compound? There is no real way. its just the formula and what you know about electronic configurations and all!
Tian_07 Posted June 1, 2004 Posted June 1, 2004 Sorry... I meant formula... like NaHSO4 or NaCl... Bad Terminology...
budullewraagh Posted June 1, 2004 Posted June 1, 2004 you just recognize the components in the compound
aommaster Posted June 1, 2004 Posted June 1, 2004 you just recognize the components in the compound which means that you are not able to tell whether they are bonded covalently or ionically. This then leads to your knowledge of electronic configuration. You can then work it out!
budullewraagh Posted June 1, 2004 Posted June 1, 2004 right. any bond involving polyatomic ions is considered ionic. any bond with an electronegativity difference greater than 1.7 is also considered ionic.
Tian_07 Posted June 1, 2004 Posted June 1, 2004 thx. ill remember the 1.7 thing... and the polyatomic ion thing i kinda knew... thx
budullewraagh Posted June 1, 2004 Posted June 1, 2004 it's all relative to one's opinion, really. every covalent bond that doesn't involve two of the same element is polar. every polar covalent bond is partially ionic. every ionic bond is partially polar covalent. a fully ionic bond is an oxymoron. if there is no sharing of the electrons involved, it's not a bond; rather, it's the transfer of electrons. the 1.7 rule is linus pauling's opinion, and what chemists use today.
Crash Posted June 2, 2004 Posted June 2, 2004 although 1.7 isnt held as hard fact......it varys. especially depending on which country and the quality of teaching on what figure your given..... Pauling's opnion is only held in high regard because he came up with the "pauling scale for electronegavity"
chemistry Posted June 3, 2004 Posted June 3, 2004 Ionic compounds typically exist as a solid, when heated they decompose yielding cation and anion gases. What you are referring to are molecular compounds, covalent compounds refer to such as graphite. The bond between ionic compounds are between the cations and anions...the elements themselves while molecular compounds form intermolecular bonds, molecule to molecule attractions. Ionic compounds are not molecules because they exist as elemental attractions in which they form crystal lattices.
budullewraagh Posted June 3, 2004 Posted June 3, 2004 Ionic compounds typically exist as a solid, when heated they decompose yielding cation and anion gases. ionic compounds tend to be between metals and halogens or nonmetal polyatomic ions. thus, they tend to not yield cation gases since the boiling points of metals are quite high.
chemistry Posted June 4, 2004 Posted June 4, 2004 Liquid phases typically do not exist in ionic compounds, that's my point. There is no need to falsely implicate what I said.
budullewraagh Posted June 4, 2004 Posted June 4, 2004 There is no need to falsely implicate what I said. calm down buddy, i just wanted to make that correction so people don't get the wrong ideas about metals and their boiling points.
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