Problem: What is the name of the following ion: H 2PO4-?

FREE Expert Solution

For this problem, we are asked to name the ion H2PO-.

First, we need to determine whether it is an ionic compound, covalent compound or an acid (binary or oxyacid). Based on its chemical formula, H2PO4- is similar to an oxyacid  

**H+ ion bonded to PO4 which is a polyatomic anion containing O. 

An oxyacid is a covalent compound that contains an H+ ion connected to a polyatomic ion containing oxygen.

Recall that the rules for naming ions are similar to naming oxyacids in gas phase (not aqueous):

1. Start with Hydrogen, write a prefix to indicate the number of H, (except for mono) 


The numerical prefixes are:

Mono – 1     Di – 2

Tri – 3          Tetra – 4

Penta – 5     Hexa – 6

Hepta – 7     Octa – 8

Nona – 9      Deca – 10


2. For Polyatomic ions they retain their name 

**no prefixes needed 

**no need to change ending to -ide 

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Problem Details

What is the name of the following ion: H 2PO4-?

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What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the Naming Acids concept. You can view video lessons to learn Naming Acids. Or if you need more Naming Acids practice, you can also practice Naming Acids practice problems.