What is meant by 'demineralised' | Class 11 Chemistry Chapter Hydrogen, Hydrogen NCERT Solutions

Question:

What is meant by 'demineralised' water and how can it be obtained?

Answer:

Demineralised water is free from all soluble mineral salts. It does not contain any anions or cations.

Demineralised water is obtained by passing water successively through a cation exchange (in the H+ form) and an anion exchange (in the OH- form) resin.

During the cation exchange process, H+exchanges for Na+, Mg2+, Ca2+, and other cations present in water.

In the anion exchange process, OH- exchanges for anions such as CO2-3, SO2-4 , Cl- , HCO-3 etc. present in water.

OH- ions liberated in reaction (2) neutralize H+ ions liberated in reaction (1), thereby forming water.

H+ (aq)  +  OH- (aq)  →   H2O(l)


Study Tips for Answering NCERT Questions:

NCERT questions are designed to test your understanding of the concepts and theories discussed in the chapter. Here are some tips to help you answer NCERT questions effectively:

  • Read the question carefully and focus on the core concept being asked.
  • Reference examples and data from the chapter when answering questions about Hydrogen.
  • Review previous year question papers to get an idea of how such questions may be framed in exams.
  • Practice answering questions within the time limit to improve your speed and accuracy.
  • Discuss your answers with your teachers or peers to get feedback and improve your understanding.

Comments

Comment(s) on this Question

Welcome to the NCERT Solutions for Class 11 Chemistry - Chapter . This page offers a step-by-step solution to the specific question from Excercise 1 , Question 26: What is meant by 'demineralised' water and how can it be obtained?....