Page 1 of 1

Test 3 Q 8

Posted: Sat Jun 02, 2018 5:14 pm
by sharonvivianv
I was asked to identify the shortest boxed bond and indicate whether it is stronger. I didn't know how to answer this because they look the same to me. Pls help

Re: Test 3 Q 8

Posted: Sat Jun 02, 2018 5:16 pm
by Mohamad Farhat 1L
the small number of elements the stronger the bond. since both have 6 bonds. 1st one has two double and two single and the second has 3 elements with 3 double bonds. which makes it stronger

Re: Test 3 Q 8

Posted: Sat Jun 02, 2018 10:23 pm
by Kuldeep Gill 1H
Since the top image includes both single and double bonds it would be longer and therefore weaker while the bottom image is composed of double bonds so it would have shorter and stronger bonds. Hope that helps!

Re: Test 3 Q 8  [ENDORSED]

Posted: Sat Jun 02, 2018 11:38 pm
by Tiffany Chen 1A
You can also think about it in terms of resonance. The first structure would have resonance (you can move the double bonds around and get the same structure), which means the double bonds are actually "spread out" throughout all the bonds. So, the actual (observed) bond of the circled bond in the first structure isn't exactly a double bond; it would be something between a single bond and double bond. In other words, that bond would be slightly weaker than a normal double bond (like the one in the second structure).

Re: Test 3 Q 8

Posted: Sun Jun 03, 2018 11:15 am
by ElizabethP1L
You were supposed to look at the double bond in relation to the entire molecule. Since SO3 consists of only double bonds it will be stronger than SO4-2 with also has single bonds that are weaker. Hope this helped! :)

Re: Test 3 Q 8

Posted: Sun Jun 03, 2018 11:39 am
by Tina Wen 1G
Yes thinking about resonance structure would help! For SO4 each S-O bond is something between single and double bond, whereas SO3 is solid double bond, which makes it stronger

Re: Test 3 Q 8

Posted: Sun Jun 03, 2018 9:21 pm
by Myles Chang 1B
I think for this question it is important to note that resonance structures are not individualized possibilities of a structure, but rather are a blend of them. Looking at the Lewis dot diagram for the top image, you could put the two double bonds in various places, meaning that the actual length (and proportionally, strength) of the bonds should be in between a single and double bond.

Re: Test 3 Q 8

Posted: Sun Jun 03, 2018 10:03 pm
by FizaBaloch1J
remember, the smaller the atom, the shorter the bond, the stronger the bond.

Re: Test 3 Q 8

Posted: Sun Jun 03, 2018 11:22 pm
by fara valdez
does that apply to all bonds?

Re: Test 3 Q 8

Posted: Sun Jun 03, 2018 11:25 pm
by Gabi Landes 1-H
So a localized double bond is essentially stronger then a delocalized bond?