Question

Identify the bonding in each of the following substances as ionic or covalent. (a) \(\mathrm{CuCl}_{2}\) (b) \(\mathrm{F}_{2}\) (c) \(\mathrm{CO}\) (d) \(\mathrm{FeCl}_{3}\)

Short answer

The bonding in the compounds are as follows: \(\mathrm{CuCl}_{2}\) - ionic, \(\mathrm{F}_{2}\) - covalent, \(\mathrm{CO}\) - covalent, \(\mathrm{FeCl}_{3}\) - ionic

Step-by-step solution

Identify the types of elements in the compound

Firstly, for each given molecule, identify whether the elements in the compound are metals, non-metals, or a mixture of them.

CuCl2

In the case of \( \mathrm{CuCl}_{2} \), there is a metal (Cu, or Copper) and a non-metal (Cl, or Chlorine). Since it's a metal bonded with a non-metal, the bond is ionic.

F2

In the case of \( \mathrm{F}_{2} \), there is only Fluorine which is a non-metal. When a non-metal bonds to a same non-metal, the bond is covalent.

CO

In the case of \( \mathrm{CO} \), both Carbon and Oxygen are non-metals. Hence, the bond is covalent.

FeCl3

In the case of \( \mathrm{FeCl}_{3} \), there is a metal (Fe, or Iron) and a non-metal (Cl, or Chlorine). Therefore, the bond is ionic.

Key concepts

Ionic Bonds

Ionic bonds are a type of chemical bonding that occurs when electrons are transferred from one atom to another. This transfer creates ions, which are atoms with a positive or negative charge. Ionic bonds typically occur between metals and non-metals. Metals tend to lose electrons and form positively charged ions, called cations. Non-metals, on the other hand, will gain these electrons to form negatively charged ions, known as anions.

The oppositely charged ions are attracted to each other, resulting in an ionic bond. This is why ionic bonds form between elements with a large difference in electronegativity, such as copper and chlorine in \( \mathrm{CuCl}_{2} \) or iron and chlorine in \( \mathrm{FeCl}_{3} \).

Ionic compounds are generally solid at room temperature and have high melting and boiling points because of the strong attraction between the ions. They are also capable of conducting electricity when dissolved in water or melted, as the ions are free to move.

Covalent Bonds

Covalent bonds form when atoms share electrons rather than transferring them. This generally occurs between non-metal atoms, which have similar electronegativities. Because they don't have a major tendency to lose or gain electrons outright, these atoms opt to share their electrons to achieve a more stable electron configuration.

For example, two fluorine atoms bond covalently in \( \mathrm{F}_{2} \), creating a molecule where each atom shares one electron, thus completing their outer shell. Another example is carbon monoxide \( \mathrm{CO} \) where a carbon atom shares electrons with an oxygen atom, forming strong covalent bonds.

Covalent compounds can exist in liquid, solid, or gaseous states based on the intermolecular forces they experience, and they typically have lower melting and boiling points compared to ionic compounds. They usually do not conduct electricity as there are no free ions in their structures.

Metal and Non-Metal Interactions

Metal and non-metal interactions often result in the formation of ionic compounds, where you see metals donating electrons to non-metals. This interaction is driven by the metal's desire to achieve a stable electron configuration by losing its valence electrons, while the non-metal seeks to gain electrons to fill its valence shell.

For example, in \( \mathrm{CuCl}_{2} \), copper, a metal, donates electrons to chlorine, a non-metal. Similarly, in \( \mathrm{FeCl}_{3} \), iron, another metal, also donates electrons to chlorine. These examples showcase classical metal and non-metal interactions leading to ionic bonds.

Such interactions characterize most of the compounds we encounter in daily life and are responsible for various materials' structural properties, like the robustness of table salt \( \mathrm{NaCl} \), which also consists of ionic bonds between a metal (sodium) and a non-metal (chlorine). Understanding these interactions helps in predicting the properties and behaviors of different substances.