Question

Define a binary molecular compound.

Short answer

A binary molecular compound is a chemical compound consisting of two distinct non-metal elements bonded together through covalent bonds. They have low melting and boiling points and generally exist as gases, liquids, or solids with low electrical conductivity. Examples of binary molecular compounds include \(H_2O\) (Water), \(CO_2\) (Carbon Dioxide), \(NH_3\) (Ammonia), and \(N_2O\) (Dinitrogen Monoxide or Nitrous Oxide).

Step-by-step solution

Definition

A binary molecular compound is a chemical compound consisting of two distinct non-metal elements, typically bonded together through covalent bonds. These compounds are composed of individual molecules in their simplest form.

Properties

Binary molecular compounds have several properties: 1. They are formed through the combination of two non-metal elements. 2. They have low melting and boiling points due to weak intermolecular forces. 3. They generally exist as gases, liquids, or solids with low electrical conductivity. 4. They are named using Greek numerical prefixes to denote the number of atoms of each element (e.g., mono-, di-, tri-).

Examples

Here are some examples of binary molecular compounds: 1. \(H_2O\) (Water): This compound is formed by the combination of hydrogen (H) and oxygen (O) elements. 2. \(CO_2\) (Carbon Dioxide): This compound consists of one carbon (C) atom and two oxygen (O) atoms. 3. \(NH_3\) (Ammonia): This compound is made up of one nitrogen (N) atom and three hydrogen (H) atoms. 4. \(N_2O\) (Dinitrogen Monoxide or Nitrous Oxide): This compound is made up of two nitrogen (N) atoms and one oxygen (O) atom. In summary, a binary molecular compound is a chemical compound formed by the bond of two non-metal elements. They are characterized by low melting and boiling points and are named using Greek numerical prefixes.

Key concepts

Covalent Bonds

Covalent bonds are a fundamental concept in chemistry, particularly when discussing binary molecular compounds. These bonds form when two non-metal elements share electrons. This sharing allows each atom to achieve a stable electron configuration, generally striving to fill their outermost shell, also known as a valence shell.

• A covalent bond is typically quite strong, which is why molecules tend to be stable once formed.
• These bonds can involve sharing one, two, or even three pairs of electrons, leading to single, double, and triple bonds.

Covalent bonds are distinct from ionic bonds, where electrons are transferred from one atom to another. Because no electrons are transferred in covalent bonds, the compound remains electrically neutral. This electron-sharing is key to forming the recognized molecular structure of a binary molecular compound such as water or carbon dioxide.

Non-metal Elements

Non-metal elements play a crucial role in the formation of binary molecular compounds. These elements are found primarily on the right side of the periodic table and include elements like hydrogen, oxygen, nitrogen, and carbon.

• Non-metals tend to have high electronegativities, meaning they tend to attract electrons.
• They often share electrons with other non-metal elements, leading to the formation of covalent bonds.

These elements contrast with metals, which are typically good conductors of electricity and heat, and often form ionic compounds when reacting with non-metals. Non-metal elements are essential in the formation of many everyday molecular substances, such as water and carbon dioxide, both of which are binary molecular compounds.

Greek Numerical Prefixes

When naming binary molecular compounds, Greek numerical prefixes help indicate the number of atoms of each element in the compound. These prefixes are a simple way to convey the composition of a molecule without needing complex formulas.

• The prefix 'mono-' signifies one atom, though it is often omitted for the first element.
• 'Di-' stands for two atoms, 'tri-' for three atoms, and so on up to 'deca-' for ten atoms.

For example, in carbon dioxide, the 'di-' prefix before "oxide" indicates there are two oxygen atoms bonded with a single carbon atom, forming CO₂. These prefixes are essential for understanding and accurately naming compounds.

Intermolecular Forces

Intermolecular forces are interactions between neighboring molecules that affect physical properties like boiling and melting points. In binary molecular compounds, these forces are relatively weak, leading to specific characteristics.

• Because of weak intermolecular forces, binary molecular compounds often have low melting and boiling points.
• They may exist in various states: gases, liquids, or solids.

The weak nature of these forces means that less energy is required to change the state of a substance. In compounds like ammonia or hydrogen gas, these weak forces play a significant role in their physical behaviors. Understanding intermolecular forces helps explain why these compounds are typically not conductive and exist at different states under standard conditions.