What makes ions soluble

Water is a polar molecule. It has a permanent dipole. The particles are then free to move around within the solution. The "shell" of water molecules reduces the attractions between the ions. The ions are hydrated. Here's a video that shows the process in action. R-Rahaman Raza. Nov 29, Explanation: An ionic compound consists of two oppositely charged ions. Related questions Question 79c2f. Question cd Question aa.

Question ae. Question 67e Substances that do not yield ions when dissolved are called nonelectrolytes. If only a relatively small fraction of the dissolved substance undergoes the ion-producing process, it is called a weak electrolyte. Substances may be identified as strong, weak, or nonelectrolytes by measuring the electrical conductance of an aqueous solution containing the substance. To conduct electricity, a substance must contain freely mobile, charged species. Most familiar is the conduction of electricity through metallic wires, in which case the mobile, charged entities are electrons.

Solutions may also conduct electricity if they contain dissolved ions, with conductivity increasing as ion concentration increases. The electrostatic attraction between an ion and a molecule with a dipole is called an ion-dipole attraction. These attractions play an important role in the dissolution of ionic compounds in water.

When ionic compounds dissolve in water, the ions in the solid separate and disperse uniformly throughout the solution because water molecules surround and solvate the ions, reducing the strong electrostatic forces between them.

This process represents a physical change known as dissociation. Under most conditions, ionic compounds will dissociate nearly completely when dissolved, and so they are classified as strong electrolytes. Let us consider what happens at the microscopic level when we add solid KCl to water.

Ion-dipole forces attract the positive hydrogen end of the polar water molecules to the negative chloride ions at the surface of the solid, and they attract the negative oxygen ends to the positive potassium ions. The reduction of the electrostatic attraction permits the independent motion of each hydrated ion in a dilute solution, resulting in an increase in the disorder of the system, as the ions change from their fixed and ordered positions in the crystal to mobile and much more disordered states in solution.

A salt is insoluble if the concentration of an aqueous solution is less than 0. Slightly soluble salts give solutions that fall between these extremes. Soluble Salts 1. The nitrate NO 3 - ion forms soluble salts. The chloride Cl - , bromide Br - , and iodide I - ions generally form soluble salts. ZnCl 2 is soluble, but CuBr is not. The sulfate SO 4 2- ion generally forms soluble salts.

Insoluble Salts 1. Sulfides S 2- are usually insoluble. Oxides O 2- are usually insoluble. Hydroxides OH - are usually insoluble. Chromates CrO 4 2- are usually insoluble.