lone pairs

(Polar molecules, Non-polar molecules, etc.)

Moderators: Chem_Mod, Chem_Admin

Brett Lieuallen 2A
Posts: 50
Joined: Wed Sep 30, 2020 9:39 pm

lone pairs

Postby Brett Lieuallen 2A » Fri Nov 13, 2020 1:57 pm

I know that lone pairs take up greater volume but could someone explain again why they take up greater volume?

Andrew Wang 1C
Posts: 89
Joined: Wed Sep 30, 2020 10:11 pm
Been upvoted: 5 times

Re: lone pairs

Postby Andrew Wang 1C » Fri Nov 13, 2020 2:01 pm

Lone pairs are only attracted by one nucleus, compared to a bonding pair which is attracted to two. This makes it so that lone pairs have a greater negative charge and thus more repulsion, which accounts for the extra "volume."

Madilyn Schindler 3E
Posts: 92
Joined: Wed Sep 30, 2020 9:52 pm
Been upvoted: 1 time

Re: lone pairs

Postby Madilyn Schindler 3E » Fri Nov 13, 2020 2:02 pm

I believe lone pairs take up more space than a bonded pair of electrons because a bonded pair has two different nuclei attracting it, making the bond smaller. On the other hand, lone pairs are only being attracted to one nucleus, therefore attracted less strongly, allowing the density of the electrons to expand. Hope that helps!

David He
Posts: 49
Joined: Wed Oct 07, 2020 12:16 am
Been upvoted: 1 time

Re: lone pairs

Postby David He » Sun Nov 15, 2020 10:40 am

First, we should know that lone pair makes an atom bigger, because electrons repel each other. If one pair of electron forms bonding, that means the electrons are attracted by other electrons, so they would no longer repel each other, making the size smaller. If you apply this idea, you will notice that long-long pair is bigger than long bonding pair than bonding bonding pair!

Michael Sun Dis 3G
Posts: 50
Joined: Wed Sep 30, 2020 9:37 pm

Re: lone pairs

Postby Michael Sun Dis 3G » Thu Nov 19, 2020 5:26 pm

Lone pairs are only restricted by the singular nucleus they are close to, while bonding pairs are restricted by two. They are thus more free in this sense, and naturally, take up a greater volume as a result.

AmyHo2K
Posts: 89
Joined: Wed Sep 30, 2020 9:39 pm

Re: lone pairs

Postby AmyHo2K » Thu Nov 19, 2020 5:30 pm

I had the same question and the responses were super helpful!

Mary Shih 3J
Posts: 96
Joined: Wed Sep 30, 2020 9:39 pm

Re: lone pairs

Postby Mary Shih 3J » Thu Nov 19, 2020 6:08 pm

Brett Lieuallen 2A wrote:I know that lone pairs take up greater volume but could someone explain again why they take up greater volume?


bonded e- only take up the space between the two elements because of its attraction to the nucleus. An unbonded pair of e- are not bound to two nuclei and therefore, have more room to move around with less constraints and attractions


Return to “Determining Molecular Shape (VSEPR)”

Who is online

Users browsing this forum: No registered users and 1 guest