Soap and Detergent MCQ Quiz - Objective Question with Answer for Soap and Detergent - Download Free PDF

The correct answer is Oleic acid.

Key Points

• Oleic acid is a monounsaturated fatty acid with a large molecular size, approximately 10^-9 meters, enabling it to form a soapy liquid.
• It is commonly found in vegetable oils such as olive oil and is known for its amphiphilic nature, meaning it has both hydrophilic and hydrophobic properties.
• The amphiphilic structure of oleic acid allows it to act as a surfactant, reducing surface tension and forming micelles in water.
• Oleic acid is widely used in soaps, detergents, and emulsifiers due to its ability to stabilize mixtures of oil and water.
• Its molecular size and properties make it suitable for applications in industries like cosmetics, pharmaceuticals, and food production.

Additional Information

• Fatty Acids:
  • Fatty acids are carboxylic acids with long hydrocarbon chains that may be saturated or unsaturated.
  • Saturated fatty acids like palmitic acid have no double bonds, while unsaturated fatty acids like oleic acid have one or more double bonds.
  • The molecular size and structure of fatty acids influence their physical and chemical properties.
• Surfactants:
  • Surfactants are compounds that lower the surface tension between two substances, such as oil and water.
  • They are commonly used in cleaning products, emulsifiers, and foaming agents.
  • Oleic acid acts as a surfactant due to its amphiphilic nature.
• Micelles:
  • Micelles are spherical structures formed when amphiphilic molecules like oleic acid aggregate in water.
  • They play a key role in the cleansing properties of soaps and detergents.
  • Micelles trap oil and dirt, making them water-soluble for easy removal during washing.
• Applications of Oleic Acid:
  • It is widely used in the cosmetic industry for formulations like moisturizers and lotions.
  • In the pharmaceutical industry, oleic acid is used as a solvent and emulsifier in drug formulations.
  • It is also utilized in the food industry as a component of cooking oils and flavoring agents.

The correct answer is interacts with hydrocarbons and interacts with water, respectively.

Key Points

• A soap molecule has two ends: a hydrophobic end and a hydrophilic end.
• The hydrophobic end is non-polar and interacts with hydrocarbons like oils and grease.
• The hydrophilic end is polar and interacts with water.
• This dual nature of soap molecules allows them to act as emulsifying agents, helping to remove oils and dirt by forming micelles.
• When soap is added to water, the hydrophobic ends of the soap molecules are attracted to the grease, while the hydrophilic ends are attracted to the water, effectively lifting and suspending the grease in the water.

 Additional Information

• interacts with water and interacts with acid, respectively
  • This option is incorrect because the hydrophilic end of the soap molecule does not specifically interact with acids; it interacts with water.
• interacts with hydrocarbons and interacts with base, respectively
  • This option is incorrect as the hydrophilic end of the soap molecule interacts with water, not bases.
• interacts with water and interacts with hydrocarbons, respectively
  • This option is incorrect because it reverses the interactions; the hydrophobic end interacts with hydrocarbons, and the hydrophilic end interacts with water.

The correct answer is Chlorine gas and dry calcium hydroxide.

Key Points

• Bleaching powder is chemically known as calcium hypochlorite (Ca(OCl)₂).
• It is prepared by the reaction of chlorine gas (Cl₂) with dry calcium hydroxide (Ca(OH)₂).
• The chemical reaction for the preparation is: Cl₂ + Ca(OH)₂ → Ca(OCl)₂ + H₂O.
• Bleaching powder is widely used for disinfecting drinking water and as a bleaching agent in the textile and paper industries.

Additional Information

• Calcium Hydroxide (Ca(OH)₂)
  • Also known as slaked lime or hydrated lime.
  • It is a colorless crystal or white powder commonly used in construction and water treatment.
• Chlorine Gas (Cl₂)
  • A greenish-yellow gas with a strong odor, used extensively for disinfection and bleaching.
  • Chlorine is a highly reactive halogen and a strong oxidizing agent.
• Calcium Hypochlorite (Ca(OCl)₂)
  • It is a white or grayish-white powder used as a disinfectant.
  • Calcium hypochlorite is also employed in swimming pool sanitation and sewage treatment.
• Disinfecting Properties
  • Bleaching powder acts by releasing chlorine, which kills bacteria and other pathogens in water.
  • It is an effective disinfectant for drinking water and is used to maintain hygiene in swimming pools.

The correct answer is It reacts with dry slaked lime to form bleaching powder..

Key Points

• Chlorine gas reacts with dry slaked lime (calcium hydroxide) to produce bleaching powder (calcium hypochlorite).
• The chemical equation for the reaction is: 2Ca(OH)₂ + 2Cl₂ → Ca(OCl)₂ + CaCl₂ + 2H₂O.
• Bleaching powder is used extensively for disinfecting drinking water and as a bleaching agent for cotton and linen in the textile industry.
• It is also used in the paper industry and for manufacturing various chemicals.

Additional Information

• Slaked Lime (Calcium Hydroxide):
  • Slaked lime, also known as calcium hydroxide, is a white powdery substance with the chemical formula Ca(OH)₂.
  • It is obtained by adding water to quicklime (calcium oxide).
  • Slaked lime is used in various industries including construction, water treatment, and food processing.
• Chlorine Gas:
  • Chlorine is a yellow-green gas at room temperature with the chemical symbol Cl₂.
  • It is a highly reactive element and a powerful oxidizing agent.
  • Chlorine is widely used in the production of disinfectants, PVC plastics, and other chemicals.
• Bleaching Powder (Calcium Hypochlorite):
  • Bleaching powder, also known as calcium hypochlorite, has the chemical formula Ca(OCl)₂.
  • It is a white or grayish-white powder with a strong chlorine odor.
  • Apart from its use in water treatment and textile bleaching, it is also used for sanitation and hygiene purposes.
• Disinfection and Bleaching:
  • Bleaching powder is effective in killing bacteria, fungi, and viruses, making it essential for water disinfection.
  • In the textile industry, it helps in whitening fabrics by removing natural color pigments and stains.
  • Proper handling and storage of bleaching powder are crucial to maintain its effectiveness and prevent accidents.

The correct answer is Chlorine gas and dry calcium hydroxide.

Key Points

• Bleaching powder is chemically known as calcium hypochlorite (Ca(OCl)₂).
• It is prepared by the reaction of chlorine gas (Cl₂) with dry calcium hydroxide (Ca(OH)₂).
• The chemical reaction for the preparation is: Cl₂ + Ca(OH)₂ → Ca(OCl)₂ + H₂O.
• Bleaching powder is widely used for disinfecting drinking water and as a bleaching agent in the textile and paper industries.

Additional Information

• Calcium Hydroxide (Ca(OH)₂)
  • Also known as slaked lime or hydrated lime.
  • It is a colorless crystal or white powder commonly used in construction and water treatment.
• Chlorine Gas (Cl₂)
  • A greenish-yellow gas with a strong odor, used extensively for disinfection and bleaching.
  • Chlorine is a highly reactive halogen and a strong oxidizing agent.
• Calcium Hypochlorite (Ca(OCl)₂)
  • It is a white or grayish-white powder used as a disinfectant.
  • Calcium hypochlorite is also employed in swimming pool sanitation and sewage treatment.
• Disinfecting Properties
  • Bleaching powder acts by releasing chlorine, which kills bacteria and other pathogens in water.
  • It is an effective disinfectant for drinking water and is used to maintain hygiene in swimming pools.

The correct answer is interacts with hydrocarbons and interacts with water, respectively.

Key Points

• A soap molecule has two ends: a hydrophobic end and a hydrophilic end.
• The hydrophobic end is non-polar and interacts with hydrocarbons like oils and grease.
• The hydrophilic end is polar and interacts with water.
• This dual nature of soap molecules allows them to act as emulsifying agents, helping to remove oils and dirt by forming micelles.
• When soap is added to water, the hydrophobic ends of the soap molecules are attracted to the grease, while the hydrophilic ends are attracted to the water, effectively lifting and suspending the grease in the water.

 Additional Information

• interacts with water and interacts with acid, respectively
  • This option is incorrect because the hydrophilic end of the soap molecule does not specifically interact with acids; it interacts with water.
• interacts with hydrocarbons and interacts with base, respectively
  • This option is incorrect as the hydrophilic end of the soap molecule interacts with water, not bases.
• interacts with water and interacts with hydrocarbons, respectively
  • This option is incorrect because it reverses the interactions; the hydrophobic end interacts with hydrocarbons, and the hydrophilic end interacts with water.

The correct answer is It reacts with dry slaked lime to form bleaching powder..

Key Points

• Chlorine gas reacts with dry slaked lime (calcium hydroxide) to produce bleaching powder (calcium hypochlorite).
• The chemical equation for the reaction is: 2Ca(OH)₂ + 2Cl₂ → Ca(OCl)₂ + CaCl₂ + 2H₂O.
• Bleaching powder is used extensively for disinfecting drinking water and as a bleaching agent for cotton and linen in the textile industry.
• It is also used in the paper industry and for manufacturing various chemicals.

Additional Information

• Slaked Lime (Calcium Hydroxide):
  • Slaked lime, also known as calcium hydroxide, is a white powdery substance with the chemical formula Ca(OH)₂.
  • It is obtained by adding water to quicklime (calcium oxide).
  • Slaked lime is used in various industries including construction, water treatment, and food processing.
• Chlorine Gas:
  • Chlorine is a yellow-green gas at room temperature with the chemical symbol Cl₂.
  • It is a highly reactive element and a powerful oxidizing agent.
  • Chlorine is widely used in the production of disinfectants, PVC plastics, and other chemicals.
• Bleaching Powder (Calcium Hypochlorite):
  • Bleaching powder, also known as calcium hypochlorite, has the chemical formula Ca(OCl)₂.
  • It is a white or grayish-white powder with a strong chlorine odor.
  • Apart from its use in water treatment and textile bleaching, it is also used for sanitation and hygiene purposes.
• Disinfection and Bleaching:
  • Bleaching powder is effective in killing bacteria, fungi, and viruses, making it essential for water disinfection.
  • In the textile industry, it helps in whitening fabrics by removing natural color pigments and stains.
  • Proper handling and storage of bleaching powder are crucial to maintain its effectiveness and prevent accidents.

CONCEPT:

Soap Molecules, Micelles, and Detergents

• Soap molecules are typically sodium or potassium salts of long-chain fatty acids. These molecules have a structure that includes both hydrophobic (water-repelling) and hydrophilic (water-attracting) ends.
• When soap is dissolved in water, it forms structures called micelles. In these micelles, the hydrophobic ends cluster together, while the hydrophilic ends face outward towards the water.
• Detergents are synthetic cleaning agents that are often more effective than soap in hard water because they do not react with calcium and magnesium ions to form insoluble precipitates.

EXPLANATION:

• Micelles are formed when soap or detergent molecules are added to water and interact with dirt or oil particles. The correct structure of micelles involves:
  • The hydrophobic (non-polar) end of the soap molecules being directed towards the oil droplet or dirt particles.
  • The hydrophilic (ionic/polar) end facing outward into the water.
• In micelles the ionic-end of the molecules is towards oil droplet while the other end faces outside is incorrect because the ionic (hydrophilic) end of the soap molecules does not face towards the oil droplet. Instead, the hydrophobic (non-polar) end is directed towards the oil droplet, while the ionic end faces outward into the water.

Therefore, the incorrect statement is In micelles the ionic-end of the molecules is towards oil droplet while the other end faces outside.