Question

What is meant by pure substance? Give types of pure substances.

Answer 1

Answer:

Pure substances:

In chemistry, pure substances have a fixed chemical composition or constant structure throughout.

For example, Water$\left({\mathrm{H}}_2\mathrm{O}\right)$, Hydrogen$\left(\mathrm{H}\right)$, Oxygen$\left(\mathrm{O}\right)$, and Gold$\left(\mathrm{Au}\right)$.

Types of pure substances: element and compound

Element:

• An element is a pure substance made up of only the same type of particles or atoms.
• It can not be split into simpler substances by chemical means.
• For example, Gold$\left(\mathrm{Au}\right)$, Silver$\left(\mathrm{Ag}\right)$, and Hydrogen$\left(\mathrm{H}\right)$.
• Gold is made up of only gold atoms, and Hydrogen gas is made up of only Hydrogen atoms.

Compound:

• A pure substance constituted of two or more elements combined chemically in a fixed ratio is called a compound.
• It can be split into these simpler and different substances by chemical means.
• For example, Water$\left({\mathrm{H}}_2\mathrm{O}\right)$.

Conclusion:

Therefore, Pure substances have a fixed chemical composition or constant structure throughout like elements and compounds.