Question

Identify the colloid and true solution from the following:

1. Vinegar
2. Muddy water
3. Mist
4. Aluminium paint

Answer 1

True solution: It is a homogeneous mixture of two or more components.

• The size of particles is less than 10^-9 m and cannot be seen with the naked eye.
• It does not show Tyndall effect.

Colloids: A colloid is a heterogeneous mixture in which the size of the particles is so small that the particles cannot be seen with the naked eye.

• The diameter of the particles of colloids lies in the range of 10^-6 and 10^-9 m.
• These particles can scatter a beam of light passing through them and make the path of light visible. This is known as the Tyndall effect.
• Examples of colloids: Milk, mist etc.
• Dispersed phase: The phase which consists of the colloidal particles and present in the smaller quantity.
• Dispersion medium: The phase in which the particles are dispersed and is present in the larger quantity.

S.No.	Substance	Identification as a true solution or colloid	Reason
1	Vinegar	True solution	Homogeneous mixture of Acetic acid $\left({\mathrm{CH}}_3\mathrm{COOH}\right)$ in Water $\left({\mathrm{H}}_2\mathrm{O}\right)$
2	Muddy water	Colloid	Heterogeneous mixture in which solid mud particles are the dispersed phase and liquid water is the dispersion medium.
3	Mist	Colloid	Heterogeneous mixture in which liquid is the dispersed phase and gas is the dispersion medium.
4	Aluminium paint	Colloid	Heterogeneous mixture in which solid Aluminium $\left(\mathrm{Al}\right)$ particles are the dispersed phase and liquid resin is the dispersion medium.