bond length

[Tiffanny_Carranza_2D]

are we supposed to know how to calculate bond length?

if so what equation or how do we do that?
thank you

[Audrey Han 3L]

I don't believe so! I think we just need to know the lengths of bonds relative to others, so a double bond is shorter than a single bond, a triple bond is shorter than a double bond, etc.

[Edward Tang 1k]

Agree with what is said above^. Maybe sometimes in resonance structures we will be asked to find the actual bond length when there are say two double bonds and one single bond that can be in any place of the three bonds, in that case we just find the average of all the bond lengths. I'm not sure why it would simply be the average but even if not it would be some value close to the average.

[MichaelMendozaD1F]

so how are we able to see which bonds are longer or smaller? like in Q11 of the sapling week 5 and 6 HW?

[Jessica Manriquez 1H]

Like most people have said, i don't think we necessarily have to know how to calculate the bond length, but we should know which bonds are longer and which bonds are shorter; so for example double bonds are shorter than single bonds, but triple bonds are shorter than double bonds, single bonds are always the longest. Hope this helped :)

[Keon Amirazodi 3H]

No, we are not. If we need to know bond lengths for to answer a question, we should be given them.

[Jaden Ji 2K]

I think the bond lengths would be given if we needed to calculate, but like what other people have been saying, to calculate the resonance structure bonds you just need to calculate the average of all the bonds (triple, double, single). The more single bonds, the longer the resonance bonds would be, and the more triple or double bonds, the shorter.

[DPatel_2L]

I don't believe we need to.

[Justin Zhang_1A]

No, bond lengths will be given in problems if we need the exact length. You should still know the relationship between bond length and strength with single, double, and triple bonds though.

[Shivani Kapur 2J]

We don't need to know how to calculate them but we do need to know which bond lengths are stronger and shorter compared to which bond lengths are longer and weaker.

[Savannah Torella 1L]

We do not need to know how to calculate for bond lengths. In lectures, Dr. Lavelle told us that the values given to us were ones that he looked up, meaning that we wouldn't be expected to find them ourselves. All you need to know is that the bonds from longest to shortest are single, double, triple and how the length compares to the strength of the bond.

[Taha 2D]

We dont need to specific bond lengths but we should know that in resonance hybrid structures all bond lengths are equal(average of the different lengths) and the higher the electron density of the bond, the shorter the bond length

[Joanne Yuh 3I]

Yeah, I don't think we need to know the exact bond length because Professor Lavelle said in his lectures that the examples of bond length are from research and that we don't need to memorize them. Also, we just need to know the general trends of bond length through atomic radius trend and other concepts.

[Kyla Roche 2K]

We don't need to know the exact numbers for bond length but know that single bonds are the longest, then double bonds, then triple bonds are the shortest. The length tells us the strength; the longer the bond, the weaker it is.

[Chance Herbert 3A]

From everything I have seen so far, the bond length is usually given. I think it would be more beneficial to know what factors contribute to bond length. For example, size of an atom may increase the bond length. Also know that the greater the bond length, the weaker the bond will be.

[Jaden Joodi 3J]

I do not believe that we are expected to calculate bond length. BUT, it is important to know trends for bond length. Know that bond length is inversely proportional to bond strength. Also make sure to remember that the larger an atom is, the larger the bond length will be.

[Sondia Luong 1C]

The bond length will most likely be given in the problem. We could use the bond length to determine which lewis structure best fits the molecule or to determine how tightly held the shared electrons are between atoms.

[Carolina Gomez 2G]

I believe we don't need to solve for the exact bond length, but it is possible to estimate what the bond length will be without having to solve for it based on information given. If a molecule has 4 bonds and three are single bonds, then the bond length will be closer to the value given for the expected bond length for single bonds and it will be within the range given for the expected single bond length to the expected double bond length.

[Haochen He 3L]

Hi, I don't think we need to calculate the actual bond length. As long as you know some characters like the longer length the weaker strength, you should be fine.

[Sarah Huang 3A]

are we supposed to know how to calculate bond length?

if so what equation or how do we do that?
thank you

Hi Tiffany!

In this class, we do not need to calculate the actual bond length, as it is usually given, both the theoretical and the experimentally observed one. However, we will be asked on the average bond length of the molecule, and when that happens, you use the theoretical bond length that is given to you. For example, if they said that C-O is 164 pm and C=O is 143 pm (these are random numbers, not official ones), and you were told to calculate the average bond length, then you would add up the total bond length and divide it by the number of bonds. If you had 1 double bond and 2 single bonds, then you would write (2(164)+1(143)/3 because you have two single bonds and 1 double bond, making a total of three bonds. Go ahead and solve it.

If you got 157pm, then you are correct!

I know you may not have needed the example, but I really hope that clarifies with what we need to do in the class.

[Rayna Irving 2C]

No, I don't think we're expected to calculate bond length as of right now, just know certain trends and ideas like triple bonds are the shortest while single bonds are the longest, and the bigger atoms have longer bond lengths when bonded with another, etc.

[Mari Williams 1K]

Do we need to know the relative lengths of other bonds like hydrogen bonds?

[Algernon Jackson 2l]

No, bond lengths are given.

[nayha a 1E]

I don't think we need to calculate the exact bond lengths, but you should know the difference between the general bond lengths. Which ones are stronger and shorter vs. weaker and longer in regards to the single, double, and triple bonds.

[Irene Nguyen 2J]

As others have mentioned, the bond length should be given to solve such. It's more important to know lengths in regards to the number of bonds, e.g Single bonds > Double bonds > Triple bonds.

[joshtully]

No, we do not need to calculate actual lengths.

[Lauren Strickland 1B]

No I do not think we have to know how to calculate bond lengths.

[Britney Tran IJ]

nope but we do need to know the length of the bonds in regards to the number of bonds

[Gustavo_Chavez_1K]

I do not think that we need to know how to calculate bond length necessarily. However, we should definitely be able to differentiate bond length based on the number of bonds. The higher the bond order (single bond, double bond, triple bond), the shorter the bond length.

[Maryeli Garay 2H]

I’m pretty sure we’re not gonna need to know how to solve for/calculate the bond length for the upcoming midterm!

[Arnav Saud 2C]

I don't think we'll need to calculate bond length for this midterm.

[Brandon McClelland3L]

We just need to be able to compare them, no exact numbers. Just know that double bonds are stronger than single bonds, and that larger molecules have weaker bonds.

[Queena Chu 3E]

We don't need to know the exact numbers but we do need to know how to compare them in terms of strength and length.

[sabrina ghalambor 2J]

we won't need to know anything exact, but know that the order from longest to shortest goes single>double>triple

[305572629]

no- all bond lengths in specific numbers should be given to us. If we ever have to figure out a bond length, just use a general periodic trend to make an estimate.

[Jacob Schwarz-Discussion 3I]

No! You just need to know the concepts. For example, multiple bonds have a shorter bond length. Weaker bonds are longer. Lone pairs on neighboring atoms also repel each other, which then in turn weakens the bond.

[Fernanda Olvera 3D]

To my understanding, we don't need to.

[Minh Nguyen 3A]

Here's hoping that all we need to know are the basic concepts behind bond length, which I'm pretty sure is the case.