Lewis structure of hydrogen phosphate HO4P-2 – Simple Procedure for Dot structures | Chemistry Net

Lewis structure of hydrogen phosphate HO4P-2 – Simple Procedure for Dot structures

Simple Method for writing Lewis Electron Dot Structures of the phosphate ion HO4P-2

Lewis structures of hydrogen phosphate HO4P-2

A simple method for writing Lewis structures is given in a previous article entitled “Lewis Structures and the Octet Rule”. Several worked examples relevant to this procedure were given in previous posts please see the Sitemap - Table of Contents (Lewis Electron Dot Structures).

Another example for writing Lewis structures following the above procedure is given in this post.

Step 1: The central atom will be the P atom since it is the less electronegative. Connect the atoms with single bonds:

The HO4P-2 atoms connected with single bond - step 1 of the method

Step 2: Calculate the # of electrons in π bonds (multiple bonds) using formula (1) in the article entitled “Lewis Structures and the Octet Rule”.:

Where n in this case is 5, excluding the H atoms. Where V = (6 + 6 + 6 + 6 + 5 + 1) – (-2) = 32 ,

V is the number of valence electrons of HO4P-2. Therefore, P = 6n + 2 – V = 6 * 5 + 2 – 32 = 0

So, there is no multiple bond in the molecule.

Step 3 & 4: The resonance structures of HO4P-2 are as follows:

Fig. 2:  Lewis electron dot structure of hydrogen phosphate HPO4-2 - Step 2 of the method

Please see the following video that shows step-by-step how to use this method to draw Lewis structures:


  1. G.N. Lewis, J.A.C.S, 38, 762-785, (1916)
  2. E. C. McGoran, J. Chem. Educ., 68, 19-23 (1991)
  3. A.B.P. Lever, J. Chem. Educ., 49, 819-821, (1972)
  4. Steven S. Zumdahl, “Chemical Principles” 6th Edition, Houghton Mifflin Company, 2009

Key Terms

Lewis structures of, simple method for writing Lewis electron dot structures, Lewis electron dot structures, electron dot structures


  1. How come the octet rule is not obeyed in the case of hydrogen phosphate?

    1. Elements below the second row of the periodic table (third, fourth..) can accommodate more than 8 electrons in the outermost shell. In the above case P has 10 valence electrons. The last Lewis structure in Fig. 2 is more favorable than the one above with 8 valence electrons around P because of less charge separation.

  2. Pi electron is zero how did we come up in having 1 multiple bond?