14 Which phrase describes a molecule of CH4, in terms of molecular polarity and distribution of charge? (1) polar with an asymmetrical distribution of charge

(2) polar with a symmetrical distribution of charge

(3) nonpolar with an asymmetrical distribl1tion of charge

(4) nonpolar with a symmetrical distribution of charge

Answer: option (4) non polar with symmetrical distribuition of charge.

Justification:

1) First you have to study the presence of dipoles.

The dipoles are polar bonds with separation of positive and negative charges.

The dipoles are formed when two different atoms each with different electronegativity form a polar bond.

In this case the chemical bonds are between C and H, i. e. C - H.

The elecronegativity of C is 2.55 and the electronegativity of H is 2.20, then the difference is 2.55 - 2.20 = 2.30. This is a small difference so the C - H bonds is generally considered non polar.

2) Now look at the geometry of the molecule.

The four C atom is at the center and the four C - H bonds around the C atom form a molecule completely symmetrical, and any charge would distributed symmetrically.