Question

Toothpaste is a _______ solution and vinegar is a __________ solution.

• A. colloidal
• B. true

Answer 1

Toothpaste is an example of a colloid.

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.

Toothpaste is a sol type of colloid in which the dispersion phase is solid and the dispersion medium is liquid as many powdered salts are present in the liquid phase.

• Dispersed phase: The phase which consists of the colloidal particles present in the smaller quantity.
• Dispersion medium: The phase in which the particles are dispersed and are present in a larger quantity.

Vinegar or Acetic acid $\left({\mathrm{CH}}_3\mathrm{COOH}\right)$ in Water $\left({\mathrm{H}}_2\mathrm{O}\right)$ is an example of a true solution.

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 the Tyndall effect.

Therefore, toothpaste is a colloidal solution and vinegar is a true solution.