Question

Classify the following as homogeneous and heterogeneous mixture:

Iodised salt

Answer 1

Iodised salt can be classified as a heterogeneous mixture.

• In iodised salt, salt or Sodium chloride $\left(\mathrm{NaCl}\right)$ is mixed physically with Iodine $\left(\mathrm{I}\right)$ in the form of some compound such as Potassium iodate $\left({\mathrm{KIO}}_3\right)$.
• Although iodised salt looks homogeneous, it is heterogeneous mixture because there is no uniformity in the composition of the mixture throughout.

Mixture: When two or more substances (elements or compounds or an element and compound) are mixed in any proportion.

Homogeneous mixture: A mixture that exhibits uniformity in its composition and properties throughout its mass is known as a homogeneous mixture.

Example: Sodium chloride $\left(\mathrm{NaCl}\right)$ solution, Sugar $\left({\mathrm{C}}_{12}{\mathrm{H}}_{22}{\mathrm{O}}_{11}\right)$ solution etc.

Heterogeneous mixture: A mixture that does not exhibit uniformity in its composition and properties throughout its mass is known as a heterogeneous mixture. Example: Muddy water, Sand and Iron $\left(\mathrm{Fe}\right)$ nails combined together.