Tag: soap

Questions Related to soap

Match the column I with column II and mark the appropriate choice.

Column I Column II
(A) $CH _3(CH _2) _{10}CH _2OS{ O }^- _3Na^+$ (i) Cationic detergent
(B) $[CH _3(CH _2) _{15}N(CH _3) _2-CH _3]^+Br^-$ (ii) Non-ionic detergent
(C) $CH _3(CH _2) _{16}COO(CH _2CH _2O) _nCH _2CH _2OH$ (iii) Soap
(D) $C _{17}H _{35}COONa$ (iv) Anionic detergent
chemistry materials we use soap and detergents soap soap and detergent

  1. (A) $\rightarrow$(iii), (B) $\rightarrow$(ii), (C) $\rightarrow$(iv), (D) $\rightarrow$(i)

  2. (A) $\rightarrow$(ii), (B) $\rightarrow$(iv), (C) $\rightarrow$(i), (D) $\rightarrow$(iii)

  3. (A) $\rightarrow$(i), (B) $\rightarrow$(iii), (C) $\rightarrow$(iv), (D) $\rightarrow$(ii)

  4. (A) $\rightarrow$(iv), (B) $\rightarrow$(i), (C) $\rightarrow$(ii), (D) $\rightarrow$(iii)

Show answer
Correct Option: D
Explanation:
  • Anionic detergents are sodium salts of sulphonated long chain alcohols or hydrocarbons. Alkyl hydrogensulphates formed by treating long chain alcohols with concentrated sulphuric acid are neutralised with alkali to form anionic detergents.
  • Here, option A which is $CH _3(CH _2) _{10}CH _2OSO^{-} _{3}Na^{+}$ Sodium laurylsulphate is an Anionic detergent.
  • Cationic detergents are quarternary ammonium salts of amines with acetates, chlorides or bromides as anions. Cationic part possess a long hydrocarbon chain and a positive charge on nitrogen atom. Hence, these are called cationic detergents.
  • Here,option B wich is $[CH _3(CH _2) _{15}N(CH _3) _2-CH _3]^{+}Br^{-}$ is a Cationic detergent.
  • Non-ionic detergents do not contain any ion in their constitution. One such detergent is formed when stearic acid reacts with polyethyleneglycol.
  • Here option C which is $CH _3(CH _2) _{16}COO(CH _2CH _2O) _nCH _2CH _2OH$ is a Non-ionic detergent.
  • Soaps are the sodium salts of long chain carboxylic acids. Here option D which is $C _{17}H _{35}COONa$ is a soap.

Glycerol is added to soap. It functions :

chemistry materials we use soap and detergents soap soap and detergent

  1. as a filler

  2. to increase lathering

  3. to prevent rapid drying

  4. to make soap granules

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Correct Option: C
Explanation:

Cleansing action of Soaps and detergents-
  • Most of the dirt is oily in nature and oil does not dissolve in water. The molecule of soap constitutes sodium or potassium salts of long chain carboxylic acids. In the case of soaps, the carbon chain dissolves in oil and the ionic end dissolves in water.
  • Glycerol is a humectant - a substance that attracts water.
  • It has the ability to draw in moisture preventing drying of the skin.
  • Hence, Glycerol is added to soap to prevent rapid drying.

What happens when a detergent is added to water?

chemistry materials we use soap and detergents soap soap and detergent

  1. Surface tension increases.

  2. Surface tension decreases.

  3. Viscosity increases.

  4. Viscosity decreases.

Show answer
Correct Option: B,C
Explanation:

When detergent is added to water, the detergent molecules break down the cohesive attractive forces of the water molecules at the surface. Thus, the surface tension is broken and viscosity increases due to attractive forces between water molecules and detergents.

Which phenomenon is/are observed during washing of clothes by detergents?

chemistry materials we use soap and detergents soap soap and detergent

  1. Micelle formation

  2. Adsorption

  3. Emulsification

  4. Foaming

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Correct Option: A,B,C,D
Explanation:

Micelle is an aggregate of surfactant molecules dispersed in a liquid colloid. A typical micelle in aqueous solution  forms an aggregate with the hydrophilic  "head" regions in contact with surrounding solvent. 
Adsorption is the adhesion of atoms, ions or molecules from a gas, liquid, or dissolved solid to a surface.
Emulsification is the process of making emulsions. Emulsions are made by shaking the dispersed phase and dispersion medium vigorously and then stabilizing the emulsion with an emulsifier. Most often soaps and detergents are added to stabilize emulsions. Stabilization is obtained by the coating of the drops of an emulsion by the stabilizer. This prevents the drops of the emulsion from combining together and separating out as a separate layer.
Foaming is the volume is expansion using air bubbles. This enables a rather lightweight material to be created even when it occupies a large volume. Also, the air layer adds heat-insulating and shock-absorbing (cushioning) properties. This happens when we apply soap while washing our clothes.
So, all phenomenon are observed during washing of cloth by detergents.
Hence, options A,B,C and D, all are correct options.

The antiseptic action of dettol is due to:

chemistry materials we use soap and detergents soap soap and detergent

  1. Chloro benzene

  2. Chloroxylenol

  3. Chloroquine

  4. Chloramphenicol

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Correct Option: B
Explanation:

The antiseptic action of dettol is due to Chloroxylenol. It also shows moderate antibacterial effects.

Why is soap referred as a salt?

chemistry materials we use soap and detergents soap soap and detergent

  1. They are long chain of fatty acids

  2. Made up of various salts

  3. Gives salt on acting with water

  4. None of above

Show answer
Correct Option: A
Explanation:

Many soaps are simply neutralized, long chain carboxylic and/or fatty acids. Usually neutralized by some mineral base. The neutralization reaction of an acid and a base produces a salt.

Which of the following is a type of soap?

chemistry materials we use soap and detergents soap soap and detergent

  1. Hard soap

  2. Soft soap

  3. Both $A$ and $B$

  4. None of above

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Correct Option: C
Explanation:

Depending upon the nature of alkali used in the production of soap, they are classified into two types.
The sodium salt of long chain fatty acid is known as hard soap.
The potassium salt of long chain fatty acid is known as soft soap, as it produces more lather.

What is salting out of soap?

chemistry materials we use soap and detergents soap soap and detergent

  1. Formation of salt

  2. Formation of acids in aqueous medium

  3. Melting if soap

  4. Precipitation of soap in solid form

Show answer
Correct Option: D
Explanation:

The saponification  reaction is exothermic in nature, because heat is liberated during the process. The soap formed remains in suspension form in the mixture. Soap is precipitated as a solid from the suspension by adding common salt to the suspension. This process is called salting out of Soap.

Process that produces soap from fats is called as:

chemistry materials we use soap and detergents soap soap and detergent

  1. acidification

  2. saponification

  3. hydrolysis

  4. condensation

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Correct Option: B
Explanation:

Soaps are sodium or potassium salts of long chain fatty acids. When triglycerides in fat/oil react with aqueous $NaOH$ or $KOH$, they are converted into soap and glycerol. This is called alkaline hydrolysis of esters. Since this reaction leads to the formation of soap, it is called the Saponification process.

_________ is used as laundry soap.

chemistry materials we use soap and detergents soap soap and detergent

  1. Hard soap

  2. Soft soap

  3. Both $A$ and $B$

  4. None of above

Show answer
Correct Option: A
Explanation:

The sodium salt of long chain fatty acid is known as hard soap. It is difficult to dissolve in water. It is used as laundry soap.