Ionic Bond Properties

At the end of the article, you will able to describe Ionic bond properties. Let’s start discussing it. Ionic Bonds are formed due to the complete transference of the electrons from one atom to another. Ions, as you already know, are formed from the loss or gain of electrons. Electrons, however, do not suddenly appear or disappear. They are, in fact, transferred from one atom to another.

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Let’s look at NaCl as an example. Na loses one electron to form a Na+ ion. The electron is not “lost”, but transferred to Cl to form a Cl- ion. So we have a Na+ ion and a Cl- ion. They are oppositely charged ions and will be electrostatically attracted to one another, much like how opposite poles of a magnet are attracted to one another. This electrostatic attraction is an ionic bond. NaCl is an ionic compound because it is held intact by ionic bonds.

Ionic Bond Properties 

Ionic Bond Properties – The compounds in which the constituent particles are held by ionic bond or known as or ionic compounds.Describe Ionic Bond Properties

Physical Appearance

In all cases, ionic compounds are hard and brittle solids at room temperature. In addition, they all form crystals with a definite shape. Here you can see a listing of the main descriptions of the crystals formed by ionic substances.

Cubic Tetragonal
Orthorhombic Triclinic
Hexagonal Trigonal
Monoclinic

These shapes can be used by scientists to determine the identity of the compound. An ionic compound that is a prime example of these properties is halite (a soft white or colorless sodium chloride NaCl ). It is a white solid that appears as cubic crystals. When force is applied, halite shatters into small crystals instead of bending or deforming. All of these properties are characteristic of ionic compounds.

Electrical Conductivity

When discussing the conductivity of ionic compounds there are three main conditions to examine-

  • Solid State
  • Molten State and
  • Dissolved State.

As solid ionic compounds fail to conduct any electricity. In other words, they are good insulators. However, if heat is applied and the solid is allowed to melt. The resulting molten form with its loose ions will conduct electricity very well. In addition, if an ionic compound is dissolved in water the dissolved ions will also be good conductors of electricity.

Reason

Ionic Bond cannot conduct electricity when they’re solids that’s because the ions cannot move they’re locked in place by the strong electrostatic forces of attraction. However, ionic compounds can conduct electricity when they’re melted or dissolved in water that’s because now the ions can move and carry the charge.

Remember

This often comes up in the exams and students frequently get this wrong. You need to remember that when ionic compounds conduct electricity it’s the ions that move not electrons.

Melting and Boiling Points

If you still need more information to make a decision as to whether or not the substance is an ionic compound. Melting and Boiling point of the ionic compound is high due the to the strong electrostatic force of attraction between oppositely charged ions. Take a look at the two tables-

Table 1 – Ionic Compounds

Compound Melting Point Boiling Point
Sodium Chloride 8010C 14130C
Potassium Iodide 6810C 13300C

Table 2 – Molecular Compounds

Compound Melting Point Boiling Point
Water 00C 1000C
Glucose 1460C
Methane -1820C -1610C
  • In Table One, we have a list of the melting and boiling points of some common ionic.
  • In Table Two, we have the same properties for the common molecular compounds.

If we compare the melting and boiling points of sodium chloride and water. We see that the melting and boiling points of sodium chloride are much higher than that of water. This is a common feature of ionic compounds compared to molecular substances. They require a large amount of energy to melt and boil.

Solubility 

Ionic compounds are soluble in water and other polar solvents. However, the ionic compounds are insoluble in non-polar solvents such as Benzene, hexene, ether etc.

In summary, there are three main things to keep in mind.

  • Firstly ionic compounds are brittle solids with definite crystal shapes.
  • Secondly, they are good insulators in their solid form and good conductors in molten or dissolved States.
  • Finally, they have high melting and boiling points compared to molecular compounds.

While individual Ionic Bond Properties may vary from one ionic compound to another. These general characteristics apply to the majority of ionic compounds and therefore can be useful when trying to determine if something is an ionic compound committing. These general properties to memory will be helpful to you in lab investigations and higher-order test questions.