Question

- The molecules methane (CH4) and ammonia both have four regions of high electron desnity around their central atoms, and yet these two molecules have different molecular geometries. Why are their molecule geometries different?

-Which of the following molecules is (are) polar? Which of the following is (are) non polar molecules that contain polar bonds? which contain nonpolar bonds?Carbon dioxide, carbon tetrafluoride, molecular chlorine, carbon monoxide, CH2O?

Answer 1

Ans 1

In CH4, CH4 has 4 sigma bonds and no lone pairs or pi bond. the Four electron pairs are contained in a
tetrahedral shape. hence, molecular geometry is tetrahedral.

In NH3, only one lone pair of electrons & three bond pairs resulting molecular geometry is trigonal pyramidal.

Ans 2

CO2 is a linear molecule, Oxygen (O) atoms are symmetrical. . Because of this symmetry and CO2 is a nonpolar molecule.

Therefore, the only intermolecular forces are London dispersion forces.

The bonds in carbon tetrachloride (CCl4) are polar, but the molecule is nonpolar because the bond polarity is canceled by the symmetric tetrahedral shape.

London dispersion forces are intermolecular forces in it