Ionic vs. Covalent Compounds​

We have heard the phrase so many times in various contexts, “Opposites attract”. However, in the case of ionic compounds, it is actually the case. In a chemical reaction, certain elements lose electrons and become positively charged, a process known as cation formation. While other elements gain electrons and become negatively charged, referred to as anions.

These opposite charges attract and form strong ionic bonds. The compounds formed by these bonds are known as “ionic compounds”.

In contrast to the aggressive transactions of ionic compounds, covalent compounds appear more friendly. They seem to believe in the phrase "sharing is caring".

So, covalent compounds form by sharing electrons. Therefore, without losing electrons, they can achieve a stable electronic configuration.

Let us take a look at the properties of ionic vs. covalent compounds and bonds so we can better identify them.

• Properties of ionic compounds

  Ionic bonds usually form between metals, which easily lose their electrons, and nonmetals, which easily gain electrons. A very common example of an ionic compound we use every day is table salt, sodium chloride (NaCl). Sodium (Na) loses one electron and becomes a sodium ion, Na⁺. Chlorine (Cl) gains one electron and becomes the chlorine ion, Cl⁻. The electrostatic attraction between Na⁺ and Cl⁻ forms NaCl.

  Some interesting properties of ionic compounds are:

  1. Ionic compounds have high melting and boiling points;
  2. They often dissolve in water;
  3. Ionic compounds conduct electricity when molten or dissolved; and
  4. They usually form crystalline solids.

• Properties of covalent compounds

  Covalent bonds are usually formed between nonmetals and nonmetals. A prime example of these compounds is water (H₂O). One oxygen shares electrons with two hydrogen atoms.

  Some interesting properties of covalent compounds are:

  1. They have lower melting and boiling points (in contrast to ionic compounds);
  2. Covalent compounds have poor electrical conductivity;
  3. They often exist as gases, liquids, or soft solids; and
  4. They do not dissociate into ions in water.

Understanding ionic vs. covalent compounds is helpful in various aspects, ranging from predicting the solubility of different compounds to identifying electrolytes versus nonelectrolytes.

• Since ionic compounds dissociate in water, you can determine if:

  • A compound dissolves;
  • A precipitate forms; or
  • Which ions remain in the solution.

• Writing net ionic equations is another significant aspect where the knowledge of ionic vs. covalent compounds comes in handy. When writing net ionic equations:

  • Soluble ionic compounds are split into ions.
  • Covalent compounds are written as whole molecules.

• Chemical reactivity of ionic compounds tells us that they participate in:

  • Precipitation reactions;
  • Acid–base reactions; and
  • Electrolyte behavior.

• Reactivity of covalent compounds is a bit different, and they behave as:

  • Reactants that remain molecular; and
  • Weak electrolytes or nonelectrolytes.

How about trying out our net ionic equation calculator and learn more about these equations.

To understand the difference between ionic and covalent compounds, let’s take a look at the features table below:

Why not read all about it in our article What are Spectator Ions? It is sure to come in handy.