Why must Roman Numerals be used when naming certain ionic compounds?
Why must Roman Numerals be used when naming certain ionic compounds?
Some elements have more then one oxidation state, some elements can form bonds with other elements by either gaining or losing more then one set number of electron. You must use roman numerals to indicate which oxidation state the element is in when that element is in a compound.
One example is Iron (Fe). Fe has the oxidation states, +2 and +3 (losing 2 and 3 elections respectively). And yes, one transferred electron can make a world of a difference.
Reply:Some elements may have more than one possible charge.
eg, Sodium, Na, is always Na+ (positive charge of one)
BUT Iron, Fe, may have multiple charges: Fe2+, Fe3+
Even though it is the same element, each of these cations (positively charged ion) is DIFFERENT, and each has different affects on substances in a reaction. (A reactant of Fe2+, will produce a different product compound than Fe3+)
So you see, it is VERY important to know which cation is being used in the reaction (otherwise you may form something that you really don't want, but either way your experimental results will be completely inaccurate.)
For this reason, we label the cations as Fe2+ or Fe(II), or Fe3+ or Fe(III).
Reply:So as not to confuse the number of atoms or moles involved.
e.g.
CuSO4
Cu(II)SO4
The Roman numeral 2 (II) indicates the oxidation state of copper; NOT the number of copper atoms, which is one. Oxygen has '4' to indicate the number of atoms present. The oxidation state of oxygen is '-2', which is not shown.
Reply:it's the International Union of Pure and Applied Chemistry's (IUPAC) procedure because certain compounds have varying oxidation states and so to distinguish one oxidation state compound from another you state the oxidation number of the cation
Reply:Because in all sciences latin is used for a universal language. So by inference, latin=roman numerals.
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