What is the formula for vanadium(V) phosphate?
Vanadium(V) phosphate is an ionic compound made up of vanadium(V) cations and phosphate anions.
The (V) Roman numeral used to name the cation indicates that vanadium, a transition metal, is in its
#"V"^(5+) ->#the vanadium(V) cation
The phosphate anion is a polyatomic ion that consists of
#"PO"_4^(3-) ->#the phophate anion
Now, vanadium(V) phosphate is a neutral compound, which means that the overall positive charge coming from the cations must be balanced by the overall negative charge coming from the anions.
In this case, you will need
#color(blue)(3)"V"^color(red)(5+) + color(red)(5)"PO"_ 4^color(blue)(3-) -> "V"_ color(blue)(3)("PO"_ 4)_color(red)(5)#
Therefore, the ionic formula for vanadium(V) phosphate will be
#"V"_3("PO"_4)_5 ->#vanadium(V) phosphate