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- Solutions 32

Predict the bond angles for all bonds in the following compounds:

(d)C_{2}H_{2}

Hey guys. So, in this one we need to go ahead and figure out the bond angle in the molecule C2H2, okay that's the formula and we know that our carbons are directly attached to each other, right? So, let's go ahead and do that and we have two hydrogens, so let's go ahead and distribute them evenly but wait guys these carbons only have two bonds, right? So what do we do? well, we can go ahead and pad two other bonds directly to the carbon since we know we can't have more than one bond to hydrogen, right? So, guys actually we can figure this out another way, right? With our IHD, so if we plugged it in 2n plus 2 minus the number of hydrogens all divided by 2, what do we get? Well, 2 times 2, right? So that's 4 plus 2, so that would be 6 minus how many hydrogens do we have? Two only, so that's 2, that's 4 divided by 2, we have 2 double bonds, right? We know, we can't have a ring because we need at least 3 carbon atoms, well, 3 atoms that can make more than one bond to have a ring, right? So guys, here what is going to be our bond angle between our hydrogen our carbon and our carbon? either way, if we go the other way it'll be the exact same thing since we have a symmetrical molecule, right? So, our H C C bond angle, what's it going to be? Guys, it's a triple bond, right? It's an SP hybridized carbon, so what does that mean if we have an SP hybridized carbon, we're going to have a 180 degree bond angle, right? It's linear. So, triple bond or two double bonds right next to each other like, you might see a molecule like this, you know, your carbon dioxide, that's also going to have a 180 degree bond angle, right? Because this is an SP hybridized carbon. Alright guys, let's move on.