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AXE formula

Posted: Sun Jun 03, 2018 10:51 pm
by danielruiz1G
is it possible to determine the shape of a molecule if you're only given the AXE formula, if so how do you do it?

Re: AXE formula

Posted: Sun Jun 03, 2018 10:54 pm
by Jessica Urzua-1H
It is possible. The AXE formula tells you how many regions of electron density there are, which ones are specifically bonding pairs, and which ones are lone pairs. This is all that is needed to determine molecular shape.

Re: AXE formula

Posted: Sun Jun 03, 2018 10:57 pm
by Jack Martinyan 1L
The chart below will be helpful

Re: AXE formula

Posted: Sun Jun 03, 2018 10:58 pm
by Enzo_1I
From what i understand it is necessary to know the shape that corresponds to the formula. This means memorizing which formulas are associated to which shape.

Re: AXE formula

Posted: Sun Jun 03, 2018 11:04 pm
by Patience Olsen 1A
Yes. A represents the center atom, X represents atoms bonded to the center atom, and E represents lone electron pairs. X and E together represent regions of electron density.
Each AXE formula corresponds to a different molecular structure shown in the chart posted by Jack.

Re: AXE formula

Posted: Sun Jun 03, 2018 11:05 pm
by Miya Lopez 1I
I believe if they give you the molecular formula and the AXE formula you could determine the shape. Say if you were given H2O: AX2E2... then you know there are 2 bonding atoms and 2 lone pairs. Then once you draw the molecule out you could figure out its shape.

Re: AXE formula

Posted: Sun Nov 18, 2018 11:00 pm
by Daniela Alvarado 3B
Enzo_1I wrote:From what i understand it is necessary to know the shape that corresponds to the formula. This means memorizing which formulas are associated to which shape.


do you happen to know if theres anyway to know the corresponding shape aside form the AXE formula? or must we memorize those too?

Re: AXE formula

Posted: Mon Nov 19, 2018 1:16 pm
by Rachel Dang 1H
There really isn't another way, the best thing to do is just memorize them because the AXE formula tells you what shape the molecule is.

Re: AXE formula

Posted: Fri Nov 23, 2018 8:36 pm
by Rami_Z_AbuQubo_2K
The only way for you to know the shapes is to simply memorize them using the table above or one that you can search up online. By knowing AXE, that should in turn help you figure out the different geometric shapes of each molecule.

Re: AXE formula

Posted: Wed Nov 28, 2018 9:09 pm
by Kyither Min 2K
Yes. With the AXE formula you can deduce what shape and bond angle the molecule will have based on charts and tables.

Re: AXE formula

Posted: Sat Dec 01, 2018 3:16 pm
by Schem_student
Also be aware that AXE is a specific VSEPR Group that will help you determine MG or molecular geometry.

Re: AXE formula

Posted: Sat Dec 01, 2018 5:19 pm
by Erin Kim 2G
yes you can determine the molecular shape of the molecule, knowing the AXE formula because the number of electron densities are known. By counting the number of lone pairs and the number of atoms around the central atom you can know the shape and bond angles.

Re: AXE formula

Posted: Sat Dec 01, 2018 5:40 pm
by 005115864
It's possible but be aware of that there are molecules with different shapes but same AXE Formula. This is because they have the same number of electron densities. For instance, tetrahedral and trigonal pyramidal are both AXE4 because they both have 4 regions of electron densities.

Re: AXE formula

Posted: Sat Dec 01, 2018 8:10 pm
by SydBenedict2H
To learn these I just made a chart, or you can write down the one posted above as it can be super helpful, and then put it all into flashcards on quilt. I studied that until i had it memorized, then, doing a bunch of problems switches the memorization from route to actual understanding.

Re: AXE formula

Posted: Sun Dec 02, 2018 8:00 pm
by Phil Timoteo 1K
Yes with the AXE formula you can determine the shape of the molecule

Re: AXE formula

Posted: Mon Dec 03, 2018 6:00 pm
by Lauren Huang 1H
Yes, the AXE formula can help you draw the shape of the structure, but it will not tell you the elements involved.

Re: AXE formula

Posted: Mon Dec 03, 2018 8:27 pm
by Arlene Linares 3A
How do we figure out the AXE formula? I am still having trouble with this.

Re: AXE formula

Posted: Thu Dec 06, 2018 6:03 pm
by Jack Hewitt 2H
danielruiz1G wrote:is it possible to determine the shape of a molecule if you're only given the AXE formula, if so how do you do it?

Yes because the AXE formula tells you the regions of electron density which is all you need to determine the shape.

Re: AXE formula

Posted: Thu Dec 06, 2018 6:05 pm
by Jack Hewitt 2H
Arlene Linares 3A wrote:How do we figure out the AXE formula? I am still having trouble with this.

A is the central atom. X is the number of atoms bonded to the central atom. E is the number of lone pairs on the central atom.

Re: AXE formula

Posted: Sat Jul 20, 2019 6:25 pm
by Zachary Menz 1D
Yes, you can determine shape with the AXE formula. You should try to memorize them because it'll save time and guarantee correctness on exams, but you can also think about it in terms of regions of electron density, where X represents bonding pairs on the central atom and E represents lone pairs on the central atom.

Re: AXE formula

Posted: Sun Nov 17, 2019 1:10 am
by Jillian C 4C
By knowing the central atom as well as how many lone pairs and bonded atoms there are, it can be deduced which shape the molecule is.

Re: AXE formula

Posted: Sun Nov 17, 2019 1:46 pm
by Jasmine 2C
Yes it is! Any molecule with the same AXE formula will have the same molecular shape/

Re: AXE formula

Posted: Sun Nov 17, 2019 4:12 pm
by Viviana Velasquez
Yes, you should be able to determine the shape of a molecule based on the AXE formula.

Re: AXE formula

Posted: Sun Nov 17, 2019 4:15 pm
by Micah3J
Is the AXE formula another name for the VSEPR formula? Are the two terms interchangeable?

Re: AXE formula

Posted: Sun Nov 17, 2019 4:17 pm
by Ayushi2011
This notation lets us know the number of bonding pairs and lone pairs which makes it easier to draw structures.

Re: AXE formula

Posted: Sun Nov 17, 2019 4:22 pm
by SarahCoufal_1k
Yes you can, and they will. usually be the same. Looking at the AXE formula, X is number of bonded pairs to central atoms and E is number of lone pairs. With this you can understand the number of electron densities but also the number of bonded atoms. So you can use both to figure out the shape and the angles usually

Re: AXE formula

Posted: Sat Nov 23, 2019 4:09 pm
by Sara Richmond 2K
danielruiz1G wrote:is it possible to determine the shape of a molecule if you're only given the AXE formula, if so how do you do it?


The only real way to do it, is to memorize the chart. This chart is especially helpful because it includes hybridization and shape and polarity.

Re: AXE formula

Posted: Sat Nov 23, 2019 11:49 pm
by Nicholas_Gladkov_2J
danielruiz1G wrote:is it possible to determine the shape of a molecule if you're only given the AXE formula, if so how do you do it?


The formula tells you how many lone pairs as well as how many attached atoms there are to the central atom.
The subscript after X is how many atoms attached to the central atom. In AX2E2 for example, there are two attached atoms.
The subscript after E refers the the number of lone pairs. For AX2E2 ther are two lone pairs.

So, putting all the information together, there are two attached atoms and two lone pairs, so we have the electron shape as tetrahedral, and the molecular shape as bent. Water has this formula. I think that as long as you know the VSEPR shapes you can deduce the formula.

Re: AXE formula

Posted: Sun Nov 24, 2019 1:28 am
by Leyna Dang 2H
Yes, it's definitely possible! You just have to be able to know which formula corresponds with which shape.

Re: AXE formula

Posted: Sun Nov 24, 2019 2:44 am
by Hannah Pham
It is possible to determine the molecular shape from AXE formula. The formula corresponds to the number of electron densities, including the lone pairs and bonds, which is then used to determine shape of the molecule.

Re: AXE formula

Posted: Sun Nov 24, 2019 3:21 pm
by sbottomley3a
Yes, you can determine the molecular shape from the formula. The subscript off of Xn tells you how many things are bonded to the central atom, and the subscript off of Em tells you how many lone pairs there are on the central atom. With this information, we can figure out the molecular shape. I suggest making flashcards from the charts posted above to make this easier! It's definitely something we need to memorize :)

Re: AXE formula

Posted: Sun Dec 01, 2019 9:25 pm
by Natalie Wang 1B
Yes, the AXE formula is part of VSEPR Theory, which is used to determine a molecule's shape. Just remember that you can't use hybridization to determine a molecule's shape!

Re: AXE formula

Posted: Sun Dec 01, 2019 9:27 pm
by Sanjana Borle 2K
The best way is to know the chart and which shape corresponds with which AXE formula.