Question

The name trisodium phosphate is incorrect for the compound Na3PO4 because ____(A) this compound should be called trisodium monophosphate.(B) the sodium has a positive 3 charge.(C) you cannot use a prefix for the first element in a molecular compound.(D) you cannot use a prefix for the first element of an ionic compound.

Answer 1

(D) you cannot use a prefix for the first element of an ionic compound.

Step-by-step explanation:

Naming of the ionic compounds:-

• The name of the cation is written first and the the name of the anion is written after the name of the cation separated by single space.
• The negative ion is written next and a suffix is added at the end of the negative ion. The suffix written is '-ide'.
• In case of transition metals, the oxidation state are written in roman numerals in bracket in front of positive ions.

Hence, given ionic compound:-

`Na_3PO_4` is formed of cation,
`Na^+` and anion,
`PO_4^(3-)`

Thus, the name must be sodium phosphate.

The name is incorrect because - (D) you cannot use a prefix for the first element of an ionic compound.