Exams › JEE Advanced › Chemistry

Which of the following statements about water softening methods is correct?

1. In Calgon's method, sodium hexametaphosphate (Na6P6O18) is used
2. In the permutit method, sodium aluminium silicate is used
3. In the synthetic resin method, all soluble minerals are removed from water
4. All of these

Correct answer: All of these

Solution

All three statements are individually correct: Calgon's method uses sodium hexametaphosphate which complexes Ca²+ and Mg²+ ions; the permutit method uses hydrated sodium aluminium silicate to exchange Na+ for hardness ions; and the synthetic resin (ion-exchange) method uses both cation and anion exchange resins to remove essentially all soluble minerals, producing demineralised water.

Related JEE Advanced Chemistry questions

• In its interactions with potassium periodate (KIO4) and hydroxylamine (NH2OH), hydrogen peroxide functions respectively as a
• Among the two isomers of hydroxybenzoic acid, the ortho isomer is a stronger acid compared to its para counterpart. Which of the following best explains this observation?
• In which of the following reactions is hydrogen gas produced?
• How many of the following compounds are classified as saline (ionic) hydrides? NaH, MgH2, CaH2, VH0.56, Fe3H, NH3
• In how many of the following processes is H2 gas released as a product? (i) Na + H2O --> (ii) KH + H2O --> (iii) CO + H2 (steam, Fe2O3/Cr2O3 catalyst) --> (iv) Electrolysis of fused (molten) NaH (v) Electrolysis of acidic water
• The wavelength of the series limit (longest wavelength limit, i.e., the convergence limit) of the Lyman series of hydrogen is x angstrom. Calculate the wave number (in angstrom⁻¹) of the third line of the Balmer series of He+ ion.

⚔️ Practice JEE Advanced Chemistry free + battle 1v1 →