Boiling point

Moderators: Chem_Mod, Chem_Admin

sarahtang4B
Posts: 132
Joined: Fri Sep 28, 2018 12:27 am

Boiling point

Postby sarahtang4B » Thu Dec 06, 2018 9:23 am

Would NH3 have a lower boiling point compared to CH4 because NH3 has a lone pair of electrons?

Courtney Quan 1C
Posts: 60
Joined: Fri Sep 28, 2018 12:26 am
Been upvoted: 2 times

Re: Boiling point

Postby Courtney Quan 1C » Thu Dec 06, 2018 9:28 am

Look at the intermolecular forces present: NH3 has the capacity to form hydrogen bonds because of its H-N bond. Hydrogen bonds, which are the strongest intermolecular forces, also have dipole-dipole and London forces (in descending order of strength of the intermolecular forces). CH4, on the other hand, only has London forces (which ALL molecules have) and is the weakest intermolecular force. As such, NH3 has a higher boiling point.

305127455
Posts: 30
Joined: Fri Sep 28, 2018 12:16 am

Re: Boiling point

Postby 305127455 » Fri Dec 07, 2018 9:44 pm

Melting and boiling point depend on intermolecular forces. NH3 is polar with its two lone-pair electrons when CH4 is not. As a result, intermolecular forces between NH3 molecules are stronger.

Chloe Likwong 2K
Posts: 70
Joined: Fri Sep 28, 2018 12:23 am

Re: Boiling point

Postby Chloe Likwong 2K » Sat Dec 08, 2018 12:17 am

To sum up the previous comments, the stronger the bond, the higher the boiling point.

Claudia Luong 4K
Posts: 59
Joined: Fri Sep 28, 2018 12:25 am

Re: Boiling point

Postby Claudia Luong 4K » Sat Dec 08, 2018 8:03 am

NH3 can have Hydrogen bonding (between H and N), dipole-dipole (due to NH3 being a polar molecule), and London dispersion forces. CH4 is nonpolar so it only has London dispersion forces. NH3 has more and also stronger intermolecular forces, so it will have a higher boiling point.

allisoncarr1i
Posts: 60
Joined: Fri Sep 28, 2018 12:15 am

Re: Boiling point

Postby allisoncarr1i » Sat Dec 08, 2018 7:49 pm

Chloe Likwong 3K wrote:To sum up the previous comments, the stronger the bond, the higher the boiling point.

Is this due to the difficulty of breaking those bonds or for a different reason?


Return to “Ionic & Covalent Bonds”

Who is online

Users browsing this forum: No registered users and 0 guests