Silver I. Copper II. Lead II. Iron II. Iron III. Hydroxide OH -. Nitrate NO 3 -. Carbonate CO 3 Sulfate SO 4 Calcium carbide. CaC 2. Its ionic formula is written as CaCl 2 , the neutral combination of these ions. Polyatomic ions are a set of covalently bonded atoms that have an overall charge, making them an ion. For example, the hydroxide ion has the formula OH Hydroxide is a compound made of oxygen and hydrogen that have been bound together.
In the process of becoming a compound, hydroxide gained an extra electron from somewhere, making it OH When creating ionic compounds with these polyatomic ions, treat them the same way as typical monatomic ions only one atom. Parentheses are always used when the compound contains multiples of the polyatomic ion. Boundless vets and curates high-quality, openly licensed content from around the Internet.
This particular resource used the following sources:. Just to add a bit more, I suppose we should first note that OH- isn't the only ion that we place in brackets. Think of something like calcium phosphate, Ca3 PO4 2. Ions that have more than one atom tend to be written in brackets, to remove ambiguity and confusion about what is actually meant.
If we didn't use the brackets in your example, we would have "CaOH2". The problem with this is that with Ca OH 2, the brackets clearly show that for each Calcium ion in the ionic lattice, there are two Hydroxide ions OH- , as EulerFan points out.
One can easily identify the cationic and anionic species, and the ratio of the two. With CaOH2, it is not completely clear what is meant. Does this mean that I have two hydrogen atoms for every one oxygen atom? Do I have a calcium bonded to a water molecule?
0コメント