Question

Define : Isomorphism

Hint:

Isomorphism depends on the "Atomic Ratio". If two compounds have different atomic ratios (e.g., NaCl and $CaCl_2$), they cannot be isomorphous.

Answer 1

Step 1: Understanding the Concept:
Isomorphism is a phenomenon where different chemical substances crystallize in the same structural form.
This usually happens when the substances have the same atomic ratio and similar chemical properties.
Step 2: Detailed Explanation:
In isomorphous substances, the constituent atoms or ions are arranged in an identical manner in the crystal lattice.
A key requirement is that the ratio of atoms in the chemical formula must be the same.
For example:
1. $NaF$ and $MgO$ (Atomic ratio 1:1)
2. $K_2SO_4$ and $K_2SeO_4$ (Atomic ratio 2:1:4)
These pairs have similar crystal shapes because the sizes and arrangement of their ions are comparable.
Step 3: Final Answer:
Isomorphism is defined as the phenomenon in which two or more substances possess the same crystal structure.