-- Posted by Sachacohen2 at 3:45 pm on May 25, 2008 How do you know if a substance is soluble or not? I mean if it ends in oxide/carbonate/hydroxide/if a an alkali metal is present??? I'm not sure -- Posted by Cyanide666 at 3:47 pm on May 25, 2008 I can try and get you a solubility chart, for points. -- Posted by WaterMolecules at 3:47 pm on May 25, 2008 My chemistry is a little rough, but it all comes down to polarity. If the molecule is polar, it will be soluble. You will need to remember which kinds of compounds are polar. The only one I can remember off the top of my head are oxides. They are definitely polar. -- Posted by Sachacohen2 at 3:49 pm on May 25, 2008 Quote: from WaterMolecules at 3:47 pm on May 25, 2008 My chemistry is a little rough, but it all comes down to polarity. If the molecule is polar, it will be soluble. You will need to remember which kinds of compounds are polar. The only one I can remember off the top of my head are oxides. They are definitely polar. what does polar mean? -- Posted by AlexRox at 3:54 pm on May 25, 2008 If an element is polar, it's got a strong charge on one side, and a weak one on the other, this difference in pull allows also polar molecules to essentially rip it apart. -- Posted by AlexRox at 3:56 pm on May 25, 2008 http://boomeria.org/chemlectures/textass2/tableA-7.jpg -- Posted by blufindr at 4:13 am on May 26, 2008 look at the structure of the formula. as a general rule, if it's a linear/tetrahedral/funny-looking one that's like the mercedes logo, it's not dissolvable. -- Posted by Sachacohen2 at 7:37 am on May 26, 2008 Quote: from AlexRox at 3:56 pm on May 25, 2008 http://boomeria.org/chemlectures/textass2/tableA-7.jpg thanks just what i was looking for