Explain why is O=C=O non polar while R-O-R is polar ?

Explanation

`CO_(2)` is a linear molecule. The dipole moment of two C=O bonds are equal and opposite and they cancel each other and hence the dipole moment of `CO_(2)` is zero and it is a non-polar molecule.

While for ethers, two dipoles are pointing in the same direction. These two dipoles do not cancel the effect of each other. Therefore, there is a finite resultant dipoles and hence R-O-R is a polar molecules.