MolSynapse / Question bank / Chemistry in Everyday Life / Cleansing agents: soaps and detergents

Cleansing agents: soaps and detergents

55 questions on Cleansing agents: soaps and detergents from the Chemistry in Everyday Life chapter: 11 NEET level, 22 JEE Main, 22 JEE Advanced. Each one opens with its answer and solution.

Practice this topic All Chemistry in Everyday Life topics

Soaps are the sodium or potassium salts of NEET level
Alkaline hydrolysis of a fat or oil to make soap also yields NEET level
Soap forms an insoluble scum in hard water because the water contains NEET level
Cetyltrimethylammonium bromide is an example of a NEET level
In a soap micelle in water, JEE Main level
Assertion (A): Sodium dodecylbenzenesulphonate can clean in hard water. Reason (R): The calcium and magnesium salts of dodecylbenzenesulphonic acid are insolubl... JEE Main level
Match the soap type in List I with its feature in List II. List I: P floating soap; Q transparent soap; R shaving soap; S laundry soap. List II: 1 made by disso... JEE Main level
Detergents with a highly branched hydrocarbon chain are a pollution problem because JEE Main level
Polyethylene glycol stearate is prepared and classified as JEE Main level
Select all correct statements. JEE Main level
A triglyceride of molar mass 890 g mol^-1 is completely saponified with NaOH according to triglyceride + 3NaOH -> glycerol + 3 soap. Taking the molar mass of Na... JEE Main level
Four unknown compounds W, X, Y, Z were examined. W: foams in distilled water, gives a white precipitate and loses foam in 0.01 M CaCl2; in water it gives a long... JEE Advanced level
Assertion (A): An aqueous solution of sodium stearate turns red litmus blue. Reason (R): The stearate ion is the conjugate base of a weak acid and is partly hyd... JEE Advanced level
Hard water contains MgSO4. Which option gives a correctly balanced equation for scum formation with sodium stearate and also the correct amount of scum obtained... JEE Advanced level
Match List I with List II. List I: P cetyltrimethylammonium bromide; Q polyethylene glycol stearate; R sodium dodecylbenzenesulphonate. List II: 1 anionic, sulp... JEE Advanced level
Select all correct statements about detergents. JEE Advanced level
A litre of hard water contains 0.0040 mol of Ca^2+. Taking the scum as calcium stearate, (C17H35COO)2Ca, select all correct statements. JEE Advanced level
A hard water contains 96 mg of Ca^2+ and 28.8 mg of Mg^2+ per litre. Each divalent ion precipitates two stearate ions as the insoluble stearate. Use atomic mass... JEE Advanced level
Soaps are the sodium or potassium salts of NEET level
The alkaline hydrolysis of a fat or oil with aqueous sodium hydroxide to give soap is called NEET level
Which compound is obtained as a by-product when a triglyceride is converted into soap by treatment with NaOH? NEET level
The hardness of water is caused mainly by dissolved salts of NEET level
Which of the following is an anionic synthetic detergent? NEET level
Cetyltrimethylammonium bromide, used in hair conditioners, is classified as a NEET level
In a sodium stearate molecule, the part that dissolves in grease and oil is NEET level
Sodium stearate solution is added to a sample of hard water containing Ca^2+ ions. The white scum that appears is JEE Main level
Ordinary soaps lose their cleansing action in strongly acidic water mainly because JEE Main level
Two synthetic detergents have the same sulphonate head. One has an unbranched dodecyl chain, the other a highly branched C12 chain. Which statement is correct? JEE Main level
Sodium lauryl sulphate is prepared in the laboratory by the following sequence: JEE Main level
A non-ionic detergent is obtained by reacting stearic acid with polyethylene glycol. The functional group that joins the hydrophobic tail to the hydrophilic cha... JEE Main level
Shaving creams contain potassium soaps rather than sodium soaps because potassium soaps JEE Main level
After saponification, sodium chloride is added to the hot reaction mixture. The purpose is to JEE Main level
When sodium palmitate dissolves in water above its critical micelle concentration, the micelles formed have JEE Main level
Match the type of soap or cleansing agent in Column I with a characteristic ingredient or property in Column II. Column I: P. Medicated soap; Q. Floating soap; ... JEE Main level
Assertion (A): Synthetic detergents can be used for washing in hard water. Reason (R): The calcium and magnesium salts of alkyl sulphates and alkylbenzenesulpho... JEE Main level
Assertion (A): Cationic detergents are the main cleaning ingredient of ordinary laundry powders. Reason (R): Cationic detergents are quaternary ammonium salts t... JEE Main level
Assertion (A): A dilute solution of sodium laurate shows a steady fall in surface tension with concentration, but above a certain concentration the surface tens... JEE Main level
Which of the following statements about soaps and synthetic detergents are correct? JEE Main level
Which of the following are anionic detergents? JEE Main level
Which statements about saponification are correct? JEE Main level
Tristearin (molar mass 890 g/mol) is saponified completely by NaOH. Use Na = 23, so sodium stearate has molar mass 306 g/mol. The mass of soap formed from 1.78 ... JEE Advanced level
A sample of 445 g of tristearin (molar mass 890 g/mol) is saponified with NaOH (Na = 23, glycerol molar mass 92 g/mol). The mass of NaOH required and the mass o... JEE Advanced level
One litre of hard water contains 2.0x10^-3 mol of Ca^2+. Sodium palmitate, C15H31COONa (molar mass 278 g/mol), is added until every calcium ion is precipitated ... JEE Advanced level
A 10 L sample of hard water contains 40 mg L^-1 of Ca^2+ and 12 mg L^-1 of Mg^2+ (Ca = 40, Mg = 24). Both ions are precipitated completely by sodium stearate (m... JEE Advanced level
Two cleansing agents were tested. Observations in 0.1% solution: Agent W: lathers in distilled water; white scum in hard water; turns cloudy on adding dilute HC... JEE Advanced level
Surface tension of aqueous solutions of an anionic surfactant at 298 K: Concentration (mM): 1, 2, 4, 8, 16, 32 Surface tension (mN/m): 60, 52, 43, 35, 34.6, 34.... JEE Advanced level
Dodecan-1-ol is treated with conc. H2SO4 and the product is neutralised with NaOH to give a surfactant Z. Which description of Z is correct according to the sta... JEE Advanced level
A non-ionic detergent C17H35COO(CH2CH2O)_nCH2CH2OH is compared with sodium stearate. Which statement is correct? JEE Advanced level
Which pair of reagents would give cetyltrimethylammonium bromide, [C16H33N(CH3)3]+ Br-, directly in one step? JEE Advanced level
Sodium stearate solution and sodium dodecylbenzenesulphonate solution are each acidified with dilute HCl. Only the first turns turbid. The best explanation is t... JEE Advanced level
A fat is heated with aqueous NaOH to give a soap A and a trihydric alcohol B. Solution of A gives a white precipitate C with CaCl2. B is then treated with a mix... JEE Advanced level
Match each type of cleansing agent in Column I with the statement in Column II that best describes it. Column I: P. Soap; Q. Anionic detergent; R. Cationic dete... JEE Advanced level
Which of the following statements about the cleansing action of soap in water are correct? JEE Advanced level
Consider the surfactants P: C15H31COONa; Q: C12H25OSO3Na; R: [C16H33N(CH3)3]+Br-; S: C17H35COO(CH2CH2O)_nCH2CH2OH. Which statements are correct? JEE Advanced level
Tristearin (molar mass 890 g/mol) is saponified completely with NaOH (sodium stearate 306 g/mol; NaOH 40 g/mol; glycerol 92 g/mol). Which statements are correct... JEE Advanced level