Class 10 Chemistry Chapter 6
Electrolysis
Important Questions

Here, you'll discover significant inquiries pertaining to Chapter 6: Electrolysis ICSE Class 10 Chemistry. These inquiries are carefully designed to aid students in preparing for the ICSE Class 10 Chemistry Examination in 2023–24. Engaging with different question formats allows students to address uncertainties, improve their exam preparedness, boost their self-assurance, and polish their ability to solve problems.

Introduction

In the ICSE Class 10 Electrolysis, you will explore topics like Electrolytes and Nonelectrolytes, Substances consisting of only Molecules, Ions, or a combination of both, an introduction to electrolysis, understanding electrolytes, electrodes, anodes, cathodes, anions, cations, oxidation, and reduction processes (in relation to electron loss and gain), a basic examination of ion migration, and practical applications of electrolysis.

What is Electrolysis ?

In ICSE Class 10 “Electrolysis” Electrolysis is a process defined as the breakdown of ionic compounds into their constituent elements by applying a continuous electric current through the compound while it's in a liquid state. During this process, cations undergo reduction at the cathode, while anions are oxidised at the anode. Essential components required for conducting electrolysis include an electrolyte, electrodes, and an external power source. Optionally, a barrier such as an ion-exchange membrane or a salt bridge may be used, mainly to prevent the products from migrating toward the opposite electrode.
For instance, when an acidic or salt-containing water solution is subjected to an electric current, it can be separated into its original elements, namely hydrogen and oxygen. Similarly, molten sodium chloride can be decomposed into sodium and chlorine atoms.
The electrolysis process is typically carried out within a vessel referred to as an "electrolytic cell," which houses two electrodes, known as the cathode and anode. These electrodes are connected to a direct current source, and the electrolyte, which is an ionic compound undergoing decomposition, can exist either in a molten state or be dissolved in an appropriate solvent. Electrodes are typically fabricated from materials like metal, graphite, or semiconductor materials, with the selection based on factors such as the chemical reactivity between the electrode and the electrolyte, as well as manufacturing cost considerations.

Class 10 Chemistry Chapter 6 Electrolysis Important Questions and Answers

Q1. A solution of cane sugar does not conduct electricity, but a solution of sodium chloride is a good conductor.

Options

(a) Sugar cane solution is a covalent compound
(b) Sodium chloride solution contains free sodium and chloride ions
(c) Sodium chloride solution migrate to positively charged electrodes
(d) All of the above

Ans. (D) All of the above

Explanation:
The sugar cane solution is a covalent compound. When it is dissolved in water, it does not dissociate to give free ions which could migrate to cathode or anode. Hence, sugar solution is a bad conductor of electricity. The sodium chloride solution mainly consists of free sodium and chloride ions which could migrate to positively charged electrodes. Hence, the solution of sodium chloride is a good conductor of electricity.

Q2. Which of the following is true in case of electrolytic refining?

Options

(a) Impure metal is made of cathode.
(b) Impure metal is made of anode.
(c) Impure metal is made from cathode and pure metal as anode.
(d) Both electrodes must be of pure metal.

Ans. (b) Impure metal is made of anode.
Explanation:
In electrolytic refining, impure metal is made the anode and a thin strip of pure metal is used as cathode.

Q3. Three different electrolytic cells A, B and C are connected in separate circuits. Electrolytic cell A contains sodium chloride solution. When the circuit is completed a bulb in the circuit glows brightly. Electrolytic cell B contains acetic acid solution and in this case the bulb in the circuit glows dimly. The electrolytic cell C contains sugar solution and the bulb does not glow. Give a reason for each of these observations.

Explanation:
I. Sodium chloride solution (NaCl) is a strong electrolyte. It dissociates almost completely when dissolved in water to give free mobile ions. Hence, NaCl conducts electricity in large quantities.
II. Acetic acid is a weak electrolyte so it conducts electricity in small quantities.
III. Sugar is a nonelectrolyte. It has only molecules and no ions. Hence, it does not allow current to pass through.

Q4. Differentiate between the following pairs based on the information given in the brackets :
(i) Conductor and electrolyte (conducting particles)
(ii) Cations and anions (formation from an atom)
(iii) Acid and Alkali (formation of type of ions)

Explanation:
(i) Conductor - conduction due to electrons; Electrolyte - conduction due to ions.
(ii) Cations are formed by the loss of electrons from an atom / or oxidation of an atom / donating electrons.
Anions are formed by the gain of electrons by an atom/reduction of an atom/ accepting electrons.
(iii) Acid - forms H+ ions or hydronium (ions in solution) or H₃O⁺ or hydrogen ions.
Alkali - forms hydroxyl (ion) or OH^- (in solution) or hydroxide ion/hydroxide.

Q5. Explain how electrolysis is an example of redox reaction.

Explanation:
(i) Conductor - conduction due to electrons; Electrolyte - conduction due to ions.
(ii) Cations are formed by the loss of electrons from an atom / or oxidation of an atom / donating electrons.
Anions are formed by the gain of electrons by an atom/reduction of an atom/ accepting electrons.
(iii) Acid - forms H+ ions or hydronium (ions in solution) or H₃O+ or hydrogen ions.
Alkali - forms hydroxyl (ion) or OH- (in solution) or hydroxide ion/hydroxide.
Cathod \(\underset{copper\space ions}{Cu^{2+}}+2e\rightarrow \underset{copper} {Cu}\)
Anode: \(Cu\rightarrow Cu^{2+}+2e.\)
Since both reduction and oxidation is happening on the same species, electrolysis is a redox reaction.

ICSE Class 10 Chemistry Chapter wise Important Questions

Conclusion

The study of "Electrolysis" in ICSE Class 10 Chemistry has illuminated the fascinating world of chemical reactions driven by electrical energy. This chapter has provided us with essential knowledge about the principles and applications of electrolysis, a process with profound significance in various fields, from chemistry to industry.Throughout this chapter, we've explored the underlying principles of electrolysis, including the concepts of ions, electrodes, and the role of electrical current in driving chemical changes. For those seeking to excel in this crucial aspect of chemistry, additional practice and resources can be instrumental. To facilitate your learning process and strengthen your grasp of electrolysis, oswal.io offers a comprehensive collection of questions and study materials.

Frequently Asked Questions

Q1 : What does the term "electrolysis" mean ?

Ans: Electrolysis is a chemical process that transpires when an electric current is introduced to a substance, resulting in the substance either gaining or losing electrons as part of a chemical reaction.

Q2: What is an electrolytic cell?

Ans:  An electrolytic cell is a setup where a positive and a negative electrode are separated and immersed in a solution that contains ions with positive and negative charges.

Q3 : In what areas is the electrolysis process applied?

Ans: Electrolysis finds extensive applications in metallurgical procedures, such as the extraction and refining of metals from various compounds, as well as in electroplating. For instance, electrolysis of molten sodium chloride yields metallic sodium and chlorine gas, while the electrolysis of water generates hydrogen and oxygen.

Q4 : Define Cathode and Anode?

Ans:  An electrode where the process of reduction occurs is referred to as the cathode whereas An electrode where the process of oxidation occurs is known as the anode.

Q5 : Describe the electrolysis process?

Ans: Electrolysis is a process where an electric current is utilised to induce a chemical transformation in a substance. This transformation involves the substance either losing or gaining an electron, which is referred to as oxidation or reduction. This process is conducted within an electrolytic cell, an apparatus comprising positive and negative electrodes separated and immersed in a solution containing ions with positive and negative charges. The substance to be changed may serve as the electrode, form part of the solution, or be dissolved within it. The flow of electric current, or electrons, enters through the negatively charged electrode known as the cathode. Positively charged constituents in the solution migrate towards the cathode, join with electrons, and undergo a conversion into neutral elements or molecules. Meanwhile, the negatively charged components within the solution move towards the other electrode, called the anode, where they relinquish their electrons and undergo a transformation into neutral elements or molecules. When the substance to be transformed serves as the electrode, the typical reaction involves the electrode dissolving as it releases electrons.