Naming the Shape
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Naming the Shape
What is one way it is easy to remember the different shape names for Lewis structure?
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Re: Naming the Shape
Generally, try to visualize the structure based on the number of bonded pairs and lone pairs. You can guess some structures from the name, eg. trigonal planar or trigonal pyramidal, but for the most part you should try to memorize the common ones. Here is a chart for your reference: https://images.tutorvista.com/cms/image ... chart1.png.
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Re: Naming the Shape
I think it is best to memorize all of the possible shapes and it would possibly help to also understand which shapes can be made from the different electron arrangements, such as an electron arrangement of trigonal planar can lead to an angular molecular shape if I am not mistaken. Just little connections like that would help.
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Re: Naming the Shape
Personally, I think that visualizing the shapes really allowed me to memorize the names of them. If you're a visual learner, there are many charts online that might help elucidate the connection between number of bonds, number of lone pairs, shapes, and the names of the shapes. One example is this chart: https://chemstuff.co.uk/academic-work/a ... molecules/
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Re: Naming the Shape
I think it's helpful but not 100% necessary to memorize the bond angles, since you can usually determine them by visualizing the shape.
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Re: Naming the Shape
I think we have to memorize the bond angles for the structures we were shown in class. I believe we're also expected to know how the angles are affected by lone pairs.
Re: Naming the Shape
Ruiting Jia 4D wrote:With the shapes, do we need to memorize the bond angles?
I think we only need to remember those basic ones, such as 109.5˚, and how change in structure (like adding lone-pair electrons) can affect them.
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Re: Naming the Shape
I think I remember him saying that we won't have to draw it, but I'm not completely sure.
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Re: Naming the Shape
mahika_nayak_3L wrote:Generally, try to visualize the structure based on the number of bonded pairs and lone pairs. You can guess some structures from the name, eg. trigonal planar or trigonal pyramidal, but for the most part you should try to memorize the common ones. Here is a chart for your reference: https://images.tutorvista.com/cms/image ... chart1.png.
thank you for the link!
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Re: Naming the Shape
There are charts that are organised in a specific way that can help with memorizing. You can google molecular shapes and be able to find a chart!
Re: Naming the Shape
the chart in the textbook is actually really helpful. As long as you can visualize it, it will be easy to remember the shapes and bond angles.
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Re: Naming the Shape
You can remember them by each electron geometries. For instance, start with AX6, which is octahedral in both electron and molecular geometry. Then replace one atom with lone pair(AX5E, which is square pyramidal, etc
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Re: Naming the Shape
Ruiting Jia 4D wrote:With the shapes, do we need to memorize the bond angles?
Exact angles in the presence of lone pairs would be determined experimentally, so you may not need to know those. But you do need to memorize the set angles, and when they become "slightly less" and "extremely less" than other angles.
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