Determine Which Molecule Is More Polar

[jeahomgrajan]

Hi, i was just wondering how to determine which molecule is more polar if you are given two, for example
CHCl3
CHBr3

you can also draw a lewis structure, which i have, but it seems no help

 

[Borek]

Try to think in terms of dipoles present in both molecules.

 

[Blueshift5]

To determine which molecule is more polar, you can calculate the difference in electronegativity between the atoms in each molecule. Electronegativity is a measure of an atom's ability to attract electrons in a covalent bond. The larger the difference in electronegativity, the more polar the bond will be.

In the case of CHCl3 and CHBr3, both molecules have the same central atom (C) bonded to three halogen atoms (Cl or Br). However, Br has a higher electronegativity than Cl, meaning the C-Br bond will be more polar than the C-Cl bond. Therefore, CHBr3 will be more polar than CHCl3.

Drawing a Lewis structure can also help in determining polarity as it shows the distribution of electrons in a molecule. In the case of CHCl3 and CHBr3, both molecules have a tetrahedral shape with a dipole moment pointing towards the more electronegative atom (Cl or Br). However, the larger difference in electronegativity in CHBr3 results in a larger dipole moment and therefore a more polar molecule.

In summary, to determine which molecule is more polar, you can calculate the difference in electronegativity or consider the molecular shape and the location of the dipole moment.