What is the correct name for the compound with the formula #CrPO_4#?

1 Answer
Mar 6, 2016

Chromium(III)phosphate

Explanation:

Since the oxidation states of #P# can be #+3or+5#, (and here it is obviously #+5#), and the oxidation state of #O# is #-2# the total charge of the phosphate will be #-3#, or #PO_4^(3-)#
It is called phosphate because of this higher state (otherwise it would be called phosphite and be #PO_3^(3+)#).
To compensate the chromium must have an oxidation state of #+3#, or #Cr^(3+)#, that's where the Lation #III# comes in (because #Cr# kan have many different oxidation numbers, up to #+7#).