These are the chemical formula of Carbon dioxide and water. We need them in our daily life. Water is a compound made up of two hydrogen atoms bonded to one oxygen atom. It is a liquid at room temperature and is essential for life on Earth. Carbon dioxide is a compound made up of one carbon atom bonded to two oxygen atoms. It is a gas at room temperature and is a byproduct of the metabolic processes of animals and the burning of fossil fuels. In this article, we will study more about what are compounds, their examples, and what are properties of compound.
1. Compounds- Meaning
In chemistry, a compound is a substance that is made up of two or more elements that are combined chemically in a fixed proportion. Compounds can be either chemical or mechanical mixtures of elements. A chemical compound is a substance that has a fixed ratio of atoms of each element and cannot be separated by physical means. A mechanical mixture is a mixture of elements that can be separated by physical means, such as filtering, centrifuging, or sieving. Examples of compounds include water (H2O), salt (NaCl), and sugar (C12H22O11). When the elements are combined, they react with one another and create chemical bonds that are difficult to break. The bonds formation are a result of atoms sharing or transferring electrons.
1.1 Types of Compound Bonds Compounds are categorized on the basis of bond that holds them together. There are primarily two categories of bonds: Covalent bonds: When two nonmetal atoms share electron pairs to create a stable bond, bonding takes place. Carbon dioxide (CO2), water, and hydrogen chloride are a few examples of covalent compounds (HCl). Ionic bond: A metal atom and a nonmetal atom exchange valence electrons to form a stable bond during bonding. Sodium bicarbonate (NaHCO3), magnesium sulphate (MgSO4), and sodium chloride (NaCl) are a few examples of ionic compounds.
2. Properties of Compounds
Compounds have a number of unique properties that are determined by the types and proportions of their constituent elements. Some of the properties of compounds include:
Compounds have a number of unique properties that are determined by the types and proportions of their constituent elements. Some of the properties of compounds include:
Melting point: The temperature at which a solid compound turns into a liquid.
Boiling point: The temperature at which a liquid compound turns into a gas.
Solubility: The ability of a compound to dissolve in a solvent to form a homogenous mixture.
Electrical conductivity: The ability of a compound to conduct electricity.
Thermal conductivity: The ability of a compound to conduct heat.
Density: The mass per unit volume of a substance.
Reactivity: The ability of a compound to participate in chemical reactions.
pH: A measure of the acidity or basicity of a compound.
Flammability: The ability of a compound to burn or support combustion.
Toxicity: The ability of a compound to cause harm to living organisms.
Components of a compound are present by mass in a specific ratio.
A compound's characteristics are distinct from those of its constituent elements.
Simple physical processes cannot separate the components of a compound.
Typically, energy is evolved in the form of heat or light with the formation of a compound.
A compound's nature is always homogeneous.
2.1 Characteristics of Covalent Compounds Many of the properties of covalent compounds are caused by intermolecular forces or the forces between different molecules of the same substance.
Covalent compounds are typically gases or liquids at room temperature. Some molecular compounds are solids at room temperature, yet they are typically pliable and mushy.
Covalent compounds often have lower melting and boiling points than ionic compounds because the forces holding them together are weaker than the forces holding the ions together in an ionic compound.
Covalent compounds prevent the electrons from moving freely, making them poor electrical conductors in general. However, certain molecules are highly reactive and can mix with other molecules to form new molecules.
The solubility of covalent compounds is often low. They are often nonpolar, which makes it difficult to dissolve them.
Covalent compounds are electrically neutral and free of ions. Due to their lack of charge and free electrons, they are poor electrical conductors. In contrast, Covalent compounds serve as good insulators.
2.2 Characteristics of Ionic Compounds
Ionic compounds are characterized by their high melting and boiling temperatures, which are caused by the strong forces holding the ions together in the lattice structure.
The ions tend to exhibit great electrical conductivity when melted or dissolved in water because they can move freely and carry an electrical charge.
The inability of the ions to flow freely results in ionic compounds being generally poor electrical conductors in the solid state.
Ionic compounds can be dissolved by polar solvents like water. Ionic chemicals cannot be dissolved by non-polar solvents like hydrocarbons and chloroform.
They are brittle and hard.
They have no electrical charge.
Key Takeaways
Key Points
There are two types of compounds- Ionic and Covalent.
Atoms are bonded together by covalent bonds in covalent or molecular compounds.
Ionic compounds are formed due to the transfer of electrons.