Welcome to the NCERT Solutions for Class 12 Chemistry - Chapter General Principles and Processes of Isolation of Elements. This page offers a step-by-step solution to the specific question from Exercise 2, Question 17: . With detailed answers and explanations for each chapter, students can strengthen their understanding and prepare confidently for exams. Ideal for CBSE and other board students, this resource will simplify your study experience.
Name the processes from which chlorine is obtained as a by-product. What will happen if an aqueous solution of NaCl is subjected to electrolysis?
In the electrolysis of molten NaCl, Cl2 is obtained at the anode as a by product.
NaCl(melt) → Na+(melt) + Cl-(melt)
At cathode: Na+(melt) + e- → Na(s)
At anode: Cl-(melt) → Cl(g) + e-
2Cl(g) → Cl2(g)
The overall reaction is as follows:
If an aqueous solution of NaCl is electrolyzed, Cl2 will be obtained at the anode but at the cathode, H2 will be obtained (instead of Na). This is because the standard reduction potential of Na (E°= - 2.71 V) is more negative than that of H2O (E° = - 0.83 V). Hence, H2O will get preference to get reduced at the cathode and as a result, H2 is evolved.
NaCl(aq) → Na+(aq) + Cl-(aq)
At cathode: 2 H2O(l) + 2e- → H2(g) + 2OH-(aq)
At anode: Cl-(melt) → Cl(g) + e-
2Cl(g) → Cl2(g)
The reaction between A and B is first order with respect to A and zero order with respect to B. Fill in the blanks in the following table:
| Experiment |
A/ mol L - 1 |
B/ mol L - 1 |
Initial rate/mol L - 1 min - 1 |
| I | 0.1 | 0.1 |
2.0 × 10 - 2 |
| II | -- | 0.2 |
4.0 × 10 - 2 |
| III | 0.4 | 0.4 | -- |
| IV | -- | 0.2 |
2.0 × 10 - 2 |
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Read MoreWelcome to the NCERT Solutions for Class 12 Chemistry - Chapter . This page offers a step-by-step solution to the specific question from Excercise 2 , Question 17: Name the processes from which chlorine is obtained as a by-product. What will happen if an aqueous s....
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