Chemical Technology Questions and Answers - Detergents

1. An example of cationic detergent is _____________
a) pyridinium derivatives
b) fatty acid amides
c) sulfonates
d) aliphatic polyhydric alcohol esters

Answer: a
Explanation:Sulfonates are examples of anionic detergents, pyridinium derivatives are cationic detergents, fatty acid amides and aliphatic polyhydric alcohol esters are non-ionic detergents.

2. Which of the following have excellent grease emulsification characteristics?
a) Detergent builders
b) Anionic detergents
c) Non-ionic detergents
d) Cationic detergents

Answer: c
Explanation: Non-ionic detergents produce little foam but have excellent grease emulsification and soil removal characteristics. Detergent builders are used for improving the characteristics of detergents.

3. Sodium carboxycellulose is used __________
a) to extend foam
b) to avoid aluminum corrosion
c) as brighteners
d) to improve soil and dirt suspension

Answer: d
Explanation: Sodium carboxycellulose is used to improve soil and dirt suspension, phosphates to extend foam; fluorescent dyes are used as brighteners, and sodium silicate to avoid aluminum corrosion.

4. Which chemical compound is not added at the stage of sodium reduction of coconut oil (detergent manufacture)?
a) Amyl alcohol
b) Xylene
c) Toluene
d) Oleum

Answer: d
Explanation: Molten sodium is added slowly to coconut oil in an aliphatic solvent generally Xylene or toluene with esterifying alcohol such as amyl alcohol.

5. Sequential steps involved in the manufacture of sodium salts of sulfated fatty alcohols are _______________
a) hydrogenation- reduction-sulfation
b) reduction-hydrogenation-sulfation
c) hydrogenation-sulfation-reduction
d) reduction-sulfation-hydrogenation

Answer: a
Explanation: In manufacture of sodium salts of sulfated fatty alcohols, first catalytic hydrogenation of coconut oil takes place followed by sodium reduction of coconut oil. Then oleum is added for sulfation of fatty alcohol.

6.Catalysts used in the catalytic hydrogenation of coconut oil are _____________
a) Nickel catalysts
b) Copper catalysts
c) Platinum catalysts
d) Cobalt catalysts

Answer: b
Explanation: Copper catalysts are used in the catalytic hydrogenation of coconut oil. Care must be taken saturation of double bonds doesn’t takes place as saturation is not suitable for manufacturing detergents.

7. Sequential steps involved in the manufacture of alkyl-aryl sulfonates are __________
a) chlorination-alkylation-sulfation
b) alkylation-chlorination-sulfonation
c) chlorination-alkylation-sulfonation
d) alkylation-chlorination-sulfation

Answer: c
Explanation: Paraffin is chlorinated to form alkyl chloride which reacts with benzene to form alkyl benzene. Alkyl benzene on sulfonation produces alkyl benzene sulfonates (ABS).

8. Manufacturing of paints involves unit processes. Is the statement true/false?
a) True
b) False

Answer: b
Explanation: The statement is wrong as manufacturing of paints, varnishes, and lacquers involves only unit operations but not unit processes. Pigments and resins manufacturing involves chemical reactions, hence unit processes.

9. Solvent used in varnishes is ________
a) Water
b) Oil
c) Alcohols
d) Ethers

Answer: b
Explanation: Water is a solvent for water-based paints. Oil is a solvent for oil-based paints and varnishes. Ethers, alcohols are solvents for lacquers.

10. Anti-foam agent in water-based paints is ___________
a) Casein
b) Pine oils
c) Chlorinated phenols
d) Poly hydroxyl phenols

Answer: b
Explanation: Casein is the dispersing agent, pine oil is the anti-foam agent, and chlorinated phenols are the preservatives in the water-based paints. Poly hydroxyl phenols are used as the anti-skinning agents.