Why is CH3+ polar?

[Chem_Mod]

Question: Why is CH3+ nonpolar even though the dipole moments don't seem to cancel out considering its shape?

[Chem_Mod]

Answer: C is slightly more electronegative than H so there is a slight dipole pointing toward C in each bond. The two side hydrogens result in a net upward dipole while the top hydrogen produces a downward dipole. These cancel out due to the trigonal planar shape leaving us with a nonpolar molecule. CH3+ is trigonal planar, so the dipole moments do cancel out.

[Raizel Ferrer 1H]

CH3+ is nonpolar, because even though C has a higher electronegative charge, the force is being pulled/shared equally between the 3 Hydrogen atoms in a trigonal planar molecular shape.

[Kati Rady-Pentek 1E]

The shape is trigonal planar b/c there are no lone pairs, hence all the dipole moments cancel out.

[AJackman]

Trigonal planar is a nonpolar shape. Even though the dipoles don't cancel out 1:1 like in square planar, the overall dipole is still 0 because the electrons are being pulled evenly in three directions.

[Edwin Montalvo 1G]

NH3+ is nonpolar because the trigonal planar structure cancels out any dipoles that exist between atoms as long as the three bonded non-central atoms are the same. In this case, we see that the carbon, being slightly more electronegative, pulls on the three hydrogens equally, and the trigonal planar structure (with three arrows pointing inwards 120 degrees apart) cancels out the magnitudes of the arrows, meaning the dipoles cancel.

[Ashley Fakolujo 3H]

Oh wow, this makes sense because I would have assumed that the two forces pointing to each other would make it non polar but Since it’s towards the central I see why it would be polar. For clarification, had the arrows been pointing away from the central atom, it would be no polar?

[chemoyku dis 1B]

Oh wow, this makes sense because I would have assumed that the two forces pointing to each other would make it non polar but Since it’s towards the central I see why it would be polar. For clarification, had the arrows been pointing away from the central atom, it would be no polar?

Hi!
For example,
BCl3 has a polar bond where Cl is slightly delta negative and Boron is slightly positive therefore the forces would be pointing away from the boron towards the Cl-. Since all three groups are the same that are bonded to boron (3 chlorines), the dipole moments should cancel out, and give a non=polar molecule.

However, if one of the groups were different so say that the molecule was not symmetrical, it would not cancel out, giving a polar molecule.

I hope this helped!

[Ashley Fakolujo 3H]

So what determines whether they are negative or positive? is that electro negativity?

[JafarriNocentelli 1G]

Because the electrons are being equally pulled in different directions by the 3 H atoms