8. Arrange the following molecules in the order of increasing polarity.

a. (PH3, HCl, H2O, CCl4)

b. (NH3, HF, H2O, HBr)

B is correct sir

thanks

a. To determine the order of increasing polarity for the given molecules:

- CCl4: Carbon tetrachloride is a nonpolar molecule due to the symmetric arrangement of four chlorine atoms around the central carbon atom.
- PH3: Phosphine is a polar molecule due to the presence of a lone pair on the central phosphorus atom, causing a bent molecular shape.
- HCl: Hydrogen chloride is a polar molecule due to the difference in electronegativity between hydrogen and chlorine atoms.
- H2O: Water is a highly polar molecule due to its bent molecular shape and the presence of two lone pairs on the central oxygen atom.

So, the increasing order of polarity would be CCl4 < PH3 < HCl < H2O.

b. To determine the order of increasing polarity for the given molecules:

- HBr: Hydrogen bromide is a polar molecule due to the difference in electronegativity between hydrogen and bromine atoms.
- NH3: Ammonia is a highly polar molecule due to its pyramidal molecular shape and the presence of a lone pair on the central nitrogen atom.
- HF: Hydrogen fluoride is a highly polar molecule due to the difference in electronegativity between hydrogen and fluorine atoms.
- H2O: Water is a highly polar molecule as mentioned before.

So, the increasing order of polarity would be HBr < NH3 < HF < H2O.

To determine the order of increasing polarity for a set of molecules, we need to consider their molecular structure and the electronegativity of the atoms involved.

The general trend for polarity is that it increases with the difference in electronegativity between the atoms in a molecule. Electronegativity is a measure of an atom's ability to attract electrons towards itself in a covalent bond. The greater the electronegativity difference, the more polar the bond.

Furthermore, the overall polarity of a molecule is influenced by both the polarity of individual bonds and the molecular geometry.

Let's analyze each set of molecules:

a. (PH3, HCl, H2O, CCl4)

In this set, we have four molecules: PH3 (phosphine), HCl (hydrochloric acid), H2O (water), and CCl4 (carbon tetrachloride).

- PH3 (phosphine) has a polar molecule due to the difference in electronegativity between phosphorus (P) and hydrogen (H). However, it is less polar than the other molecules in this set.
- HCl (hydrochloric acid) has a higher polarity because of the significant electronegativity difference between chlorine (Cl) and hydrogen (H).
- H2O (water) has an even higher polarity due to the electronegativity difference between oxygen (O) and hydrogen (H).
- CCl4 (carbon tetrachloride) is nonpolar because the chlorine atoms have the same electronegativity and cancel out the polarity.

So, the correct order of increasing polarity for set a is:

PH3 < CCl4 < HCl < H2O

b. (NH3, HF, H2O, HBr)

In this set, we have four molecules: NH3 (ammonia), HF (hydrogen fluoride), H2O (water), and HBr (hydrobromic acid).

- NH3 (ammonia) has a polar molecule due to the difference in electronegativity between nitrogen (N) and hydrogen (H). However, it is less polar than the other molecules in this set.
- HF (hydrogen fluoride) has a higher polarity because of the significant electronegativity difference between fluorine (F) and hydrogen (H).
- H2O (water) has an even higher polarity due to the electronegativity difference between oxygen (O) and hydrogen (H).
- HBr (hydrobromic acid) has the highest polarity among the given molecules because of the significant electronegativity difference between bromine (Br) and hydrogen (H).

So, the correct order of increasing polarity for set b is:

NH3 < H2O < HF < HBr

Remember, when determining the order of increasing polarity, it's essential to consider both the electronegativity difference and the molecular structure of the molecules in question.