Hybridization and Molecular Geometry (AP Chem)

Test Preparation AP Sciences
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<p>How would you visualize the types of hybridization and molecular geometry because that's what I am currently having trouble with for the Exam?</p>

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<p>Ok, lets see if I can explain this correctly… for hybridization, just count all the bonding and nonbonding electron pairs of the molecule. If you don’t know how many they have, you have to draw the Lewis structure!</p>

<p>Double and triple bonds count as one. So, if I have a BF3 molecule that is trigonal planar, it has three bonding pairs. It has no nonbonding electron pairs. 3 + 0 = 3 This means the hybridization will be sp2. </p>

<p>Same would go for a bent molecule with 2 bonds and 1 non bonding electron pair. Together that is three. So 3 is sp2. </p>

<p>For tetrahedral, there are four bonds. Four is always sp3
Same would go for trigonal pyramidal, because there are 3 bonds, then 1 nonbonding electron pair, which together is 4.</p>

<p>You might see a pattern that a certain shape will have a certain hybridization. But this is NOT true! For example a bent molecule can have 2 bonds and 2 nonbonding electron pairs. Together that is 4. And what is 4? sp3!</p>

<p>Alternatively you could memorize the hybridization by things like “AX5E1 is always sp3d2” but I feel that’s unnecessary </p>

<p>So basically…
sp: 2
sp2: 3
sp3: 4
sp3d: 5
sp3d2: 6</p>

<p>How to get the numbers?
Add the bonds and nonbonding electron pairs together.
Double and triple bonds count as ONE.</p>

<p>One last example: </p>

<p>Try drawing the structure for I3^-1
You will see that it is linear. It has 2 bonds. It has 3 nonbonding electron pairs. 2 + 3 = 5. What is 5? sp3d2. </p>

<p>I’m sure there are a bunch of another ways but I find this the simplest and I hope I helped!</p>

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<p>Thank you! I understand it more now.</p>

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<p>You’re welcome! Also I just noticed I accidentally said sp3d2 for I3^-1! It’s sp3d because sp3d is 5!</p>

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<p>How does everyone here memorize all of the molecular geometries (Square Planar, T-Shaped, Seesaw)? I think I have the main ones down, but I’m having trouble remembering the ones with nonbonding electron pairs.</p>

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<p>You can try visualizing? Honestly, that’s hard for me too >.<</p>

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<p>Yeah, some people say that they can just tell what the molecular geometry is simply by looking at it. Personally, I cannot…</p>

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<p>It’s just something you have to memorize, I guess. All it really is, is counting bonding and nonbonding electron pairs! My teacher made a sheet and I’ll try to scan it for you guys</p>

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<p>Feed on this. lol <a href=“http://qsib.files.■■■■■■■■■■■■■/2010/02/vsepr_geometries1.png[/url]”>http://qsib.files.■■■■■■■■■■■■■/2010/02/vsepr_geometries1.png&lt;/a&gt;&lt;/p&gt;

<p>Steric no should be hybridization or electron geometry while basic geometry is molecular geometry! Hope this helps!</p>

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<p>For the hybridization my teacher just told us to count each specific bond on an atom as s, sp, sp2, etc. I know that sounds completely wrong, but its easier in person. For example, you have CO2:</p>

<pre><code> O=C=O the double bond in front of C counts as S, and the other as SP, so you would have an SP hybridization. Upaired electrons on the central atom also count as another hybridization level. (At least im pretty sure it does)
</code></pre>

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