Briefly explain why potassium chloride readily disolves in water? Include a sketch of the water molecule
Showing its polarity.
Potassium chloride (KCl) readily dissolves in water due to the polar nature of the water molecule. Water (H2O) is a bent molecule with an oxygen atom covalently bonded to two hydrogen atoms. Each hydrogen atom forms a polar covalent bond with the oxygen atom, resulting in a slightly positive charge on the hydrogen atoms and a slightly negative charge on the oxygen atom.
Here's a sketch of a water molecule, indicating its polarity:
H
|
O
|
H
The oxygen atom has a slightly negative charge (δ-) due to its higher electronegativity, while each hydrogen atom carries a slightly positive charge (δ+). This polarity gives water its unique ability to dissolve many different substances.
When KCl is added to water, the polar water molecules surround and interact with the K+ and Cl- ions due to the principle of "like dissolves like." The slightly positive hydrogen ends of the water molecules are attracted to the negatively charged chloride ions (Cl-), while the slightly negative oxygen ends are attracted to the positively charged potassium ions (K+).
The water molecules effectively surround and separate the K+ and Cl- ions, pulling them away from each other and breaking the ionic bond in KCl. This process is called hydration or solvation, and it allows the individual ions to be dispersed uniformly throughout the water, resulting in the dissolution of potassium chloride.
Overall, the polar nature of the water molecule enables it to interact favorably with the ionic bonds of KCl, facilitating its dissolution in water.