Lewis Electron Dot Structure of
Chromic Acid H2CrO4
A simple procedure for writing Lewis electron dot 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 below.
Let us consider the case of the Lewis electron dot structures of chromic acid H2CrO4. Chromic acid is a strong acid and an oxidizing agent. In oxidation reactions, the chromium atom is reduced from the hexavalent to the trivalent state. It is used as an intermediate in chromium plating, as a strong oxidizing agent in organic synthesis, as wood preservative, for the preparation of other chrome chemicals of analytical grade and for the cleaning of laboratory glassware.
How can we draw the Lewis electron dot structures of chromic acid H2CrO4?
Step 1: Connect the atoms with single bonds.
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 = (1 + 6 + 6 + 6+ 6 + 6 + 1) = 32 , V is the number of valence electrons of the molecule.
Therefore, P = 6n + 2 – V = 6 * 5 + 2 – 32 = 0 So, there is no multiple bond in the molecule.
Step 3 & 4: The Lewis resonance structures of chromic acid H2CrO4 are as follows:
