Memorizing VSEPR Shapes

[Anne Mariano 3F]

Hello,
Are there any mnemonic devices or ways you remember the VSEPR shapes in terms of knowing how many lone pairs each has. I sometimes mix up the shapes that have 5 or 6 domains.

[Ayaan_Ekram_2J]

Hello!

I don't think there is a mnemonic device but I find it helpful to try to create a table from memory where you start with the parent shapes (trigonal planar, tetrahedral, trigonal bipyramidal, and octahedral) and replace one atom with one lone pair at a time, naming them on the way. This helps with understanding how the shapes work, which makes naming very easy. It also helps if you draw the 3-D structures as you make this table as they help you visualize why they are named that specific way. I hope this helps!

[Tylina Guo 1K]

I think it's easiest to review how Dr. Lavelle went over them in class by understanding that atoms bonded to the center atom want to be as far away from each other as possible and the shape names are pretty descriptive/accurate to the actual shape.

[BB Dis 1H]

Hello!

I don't think there is a mnemonic device but I find it helpful to try to create a table from memory where you start with the parent shapes (trigonal planar, tetrahedral, trigonal bipyramidal, and octahedral) and replace one atom with one lone pair at a time, naming them on the way. This helps with understanding how the shapes work, which makes naming very easy. It also helps if you draw the 3-D structures as you make this table as they help you visualize why they are named that specific way. I hope this helps!

This is exactly how I do it to! I just start with the basic ones and manipulate a different part of it each time to get the more complex shapes. It makes it a lot easier to understand :)

[amar_151]

The names of the molecular geometry are very helpful to link the VSEPR formula to the shape. For example, seesaw has 4 atoms bonded to the central atom and one loan pair. If you visualize a seesaw, you can put together that 2 atoms belong in the axial position and the other 2 belong in the equatorial position. I envision the seesaw moving back and forth as the loan pair on top moves side to side. I definitely recommend trying to visualize and make sense of the VSEPR shapes rather than memorizing them. This has helped me with long-term memory of VSEPR.

[Desiree Eshraghi 3A]

What I did was similar to another suggestion. I made an a abbreviated table and then timed myself in how fast I can recreate it from memory. I would write it on my scratch paper when a relevant question came up.

[Iman Gauhar 3E]

Hi! I don't have a mnemonic device but it helps me to associate each specific electric geometry with each A-X-E formula. I also like to draw out the molecules because visualizing the shape always tends to help me remember the names.

[Aashna Sibal 2F]

Although I don't have one specific way to memorize all the shapes, I find that the easiest way to remember them is to practice drawing them out on a table and doing practice problems. Over time, it makes it much easier to remember the shapes.

[Carlie_Dorostkar_1A]

Thank you! All these tips were really helpful for me!

[Sally_Luo_3F]

Hi,
For me, I start with memorizing the parent shapes and memorizing their prefix (linear -2, tri-3, tetra-4), and then I would add the lone pairs. I did a lot of practice of each type of molecular shape so I know what every one of them looks like. Then I would memorize the visual of those shapes and try to recall it when I'm doing questions.

[Isabelle Kludt 2B]

I think looking at the chart helps but it really helps me to think about it visually and in a 3D way like why it would make those shapes so you don't have to worry about memorizing if it makes sense looking at it.

[PatrickV]

How I memorized them was by going over a VSEPR chart and using the A, X and E and memorizing what each shape is. A is the central atom, X are the atoms connected to the central atom, and E is the number of lone pairs.