What is the Lewis structure for HClO3?

Answer 1

This is all about the imaginable solutions for the possible Lewis structure of chlorate, ClO3-.

You may think: Since Cl is more electronegative than O, stick Cl in the middle, connect the 3 O's to it, and add one lone pair to the Cl to fill its octet, as well as 3 lone pairs to each O to fill their octets. Now, you have 3 bonds, 10 lone pairs, summing to 26 valence electrons, which is what we started with.

This looks simple but is not correct: The octet rule is violated and no place of the negative charge is given.

Corrected: Chlorine, the most electronegative, is mid-centered. The whole ion structure has 26 valence electrons available for bonding and lone pairs (7 from chlorine + (3×6) from the three O atoms + 1 from the negativecharge).

First: One O is single bonded (2) to Cl with three lone pairs on oxygen (6). (This O-atom carries the negative charge of the chlorate anion).

Second: the other two O have a double bond (2×4), each with two lone electron pairs (2×4).

The last two electrons (2) go to a lone pair on Cl.

When you add up all bold-italic numbers you'll get 26.

Please view the Lewis structure (also of three resonance structures) in 'Related links' down this answering page. A figure can be more convincing than 100 words.

Accounting for formal chargeThe problem with Lewis structures is that sometimes you will have two or more perfectly valid structures that are different. In these cases, it is useful to account for formal charge. The rule of thumb for formal charge: the Lewis structure that minimizes formal charge tends to be the correct structure.

Formal charge can be calculated by taking the number of valence electrons an atom in a molecule "came with" and subtracting the number of lone pair electrons and half of the bonded electrons.

So take the first example in which you achieve a valid structure through single bonds. The central chlorine atom comes in with 7 valence electrons. It has one lone pair (2) and shares (3) electrons in three single bonds. Chlorine's formal charge is 7-5 = 2. Then take an oxygen, which comes in with 6 valence electrons. It has three lone pairs (6 electrons) and shares (1) electron in a single bond. Its formal charge is 6-7 = -1. All three oxygen atoms will then have a formal charge of -1. (Note that when you add up the formal charges, you get the overall charge of the ion).

Now account for the formal charge in the second structure. You will note that the formal charge for the chlorine, the double bonded oxygens, and the single bonded oxygens is 0, 0, and -1 respectively.

Going back to our rule of thumb (the structure that minimizes formal charge is correct), we see that the second structure with two double-bonded oxygens is the most likely structure.
The Lewis dot structure of ClO3- starts with a Cl for the chlorine atom in the center. Around this are drawn 3 O atoms. Two of the oxygen atoms are joined to the chlorine with double dashes, and the third is joined with a single dash. To finish, the chlorine atom receives two dots on its unjoined side, each doubly bonded oxygen atom receives two sets of two dots and the singly bonded oxygen gets three sets of double dots.

Answer 2

you cant hav 1... ONLY FOR ELEMENTS that's an anion, not a compound. you can make dot diagrams for any ion, atom or compound. the bigger they are the harder they are. put the extra electron onto the chlorine, which is central. bump the oxygens in from three sides, all oxygen electrons out. the "bond" will be two electrons from Cl to each oxygen, called coordinate covalent bonds. oxygen doesn't have enough electrons to share, chlorine can't make more than one "normal" covalent bond, this is the only way.

Answer 3

http://www.chemeddl.org/labs/avisualdatabase/data/png/hclo3.png

Answer 4

stop cheating and figure it out.

Answer 5

tetradrical