Question #10d32

Oct 23, 2015

You don't need Roman numerals for this compound.

Explanation:

If I understand your question correctly, then you don't need to use Roman numerals to name this ionic compound.

Roman numerals are only used for ionic compounds formed with metals that do not belong to group 1 or group 2 of the periodic table.

In this case, beryllium, $\text{Be}$, is located in group 2, so you don't need to use a Roman numeral.

The idea with Roman numerals is that they are used in the name of an ionic compound when the metal can exhibit multiple oxidation states.

In essence, Roman numerals are a way of distinguishing between various oxidation states in which a transition metal, for example, can exhibit.

Since beryllium is located in group 2, it can only exhibit a $+ 2$ oxidation state, so there's no need to distinguish between any other possible oxidation states because this is the only one beryllium has.

Your ionic compound is formed when one beryllium cation, ${\text{Be}}^{2 +}$, bonds ioncially to two bicarbonate anions, ${\text{HCO}}_{3}^{-}$.

Notice that the subscripts of the ions are equivalent to their charges (in absoltue value)

${\text{Be"_color(blue)(1)("HCO"_3)_color(red)(2) -> "Be"^color(red)(2+) + 2 * "HCO"_3}}^{\textcolor{b l u e}{1 -}}$

The name of this compound will thus be beryllium bicarbonate.