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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: vanderwaals on February 03, 2017, 09:05:50 PM

Title: Dipole Moment of NF3 and NCl3
Post by: vanderwaals on February 03, 2017, 09:05:50 PM
Why does NCl3 have a greater dipole moment than NF3? It seems to make more sense for NF3 to have the greater dipole moment because F is more electronegative than Cl, and both molecules have the same molecular geometry (trigonal pyramidal).
Title: Re: Dipole Moment of NF3 and NCl3
Post by: AWK on February 03, 2017, 09:45:16 PM
Pay attention to the difference in bond legths.
Title: Re: Dipole Moment of NF3 and NCl3
Post by: vanderwaals on February 04, 2017, 12:15:59 AM
Thanks for the helpful response! How would you know if the increase in bond length has a greater effect than a decrease in electronegativity? For example, HF has a greater dipole moment than HCl even though HF has a smaller bond length. How do you know which factor dominates?