Select the correct option with regard to the following statements (S1 and S2) pertaining to two types of paints.
S1: In plastic paint, the thinner used is oil.
S2: Varnish is a homogenous solution of resin in alcohol.
Try it first: pick an option, then read the explanation.
The Liquid Part of Coatings: Solvent vs. Thinner
Understanding the liquid components of paints and varnishes is key to this question. The solvent is the liquid that dissolves the binder (the film-forming resin). The thinner is a liquid added to reduce the viscosity (thickness) of the coating for easier application. Often, the solvent and thinner are the same liquid.
Detailed Analysis of the Statements
Statement S1: In plastic paint, the thinner used is oil.
Analysis: "Plastic paint" is a common term for modern water-based paints, also known as latex or emulsion paints. In these paints, the binder is a synthetic polymer (like acrylic or vinyl) dispersed in water. The liquid carrier, solvent, and thinner for these paints is water. Oil is the characteristic thinner for traditional oil-based paints, not water-based plastic paints.
Conclusion: Therefore, statement S1 is FALSE.
Statement S2: Varnish is a homogenous solution of resin in alcohol.
Analysis: Varnish is defined as a solution of a resin in a solvent. The type of solvent determines the type of varnish. A varnish made with alcohol as the solvent is called a spirit varnish (French polish is a famous example). Since a spirit varnish is a valid and common type of varnish, the statement that "Varnish is a homogenous solution of resin in alcohol" is a correct description of one type of varnish. It doesn't claim it's the *only* type.
Conclusion: Therefore, statement S2 is TRUE.
Final Verdict
Since S1 is false and S2 is true, the correct option is (a). The question tests the fundamental difference between water-based paints (like plastic paint) and the composition of a specific type of varnish (spirit varnish).
Comparison: Plastic Paint vs. Varnish
| Property | Plastic Paint | Varnish (Spirit Type) |
|---|---|---|
| Appearance | Opaque (has pigments) | Transparent (no pigments) |
| Binder | Acrylic/Vinyl Polymer | Natural Resin (e.g., Shellac) |
| Thinner/Solvent | Water | Alcohol (Spirit) |
| Primary Use | Walls and ceilings | Finishing fine wood furniture |