Question

The dipole moment of co2 is zero even though the c-o bond is polar, why?

Answer 1

CO2 is a linear molecule, so our dipoles are symmetrical; the dipoles are equal in magnitude but point in opposite directions. co2 has linear shape like shown in the image. Due to this shape the dipoles of two oxygen atoms cancel each other and that is why CO2 has 0 dipole moment.

(not mine)