Electrolysis Intex-1 Concise Class-10 ICSE Chemistry Selina Solutions Chapter-6. We Provide Step by Step Answer of Intex-1 Questions of Exercise-6 for ICSE Class-10. The given Solutions are according to the Latest editions. Visit the official Website CISCE for detail information about ICSE Board Class-10.
Electrolysis Intex-1 Concise Class-10 ICSE Chemistry Selina Solutions Chapter-6
| Board | ICSE |
| Book / Publication | Concise / Selina |
| Subject | Chemistry |
| Class | 10th |
| Writer | Dr SP Singh |
| Chapter-6 | Electrolysis |
| Topics | Intex-1 |
| Edition | 2025-2026 |
Intex-1 Questions on Electrolysis
Page-109
Que-1: Fill in the blanks:
(a) Powdered sodium chloride (common salt) does not conduct an electric current, but it does so when ____ or when _____.
(b) Molten lead bromide conducts electricity. It is called an____. It is composed of lead ____ and bromide _____. The lead ions are ____charged and are called_____. The bromide ____ are _____ charged and are called ______.
(c) Substances which conduct electricity in the solid state are generally ______.
(d) The electron releasing tendency of zinc is _____than that of copper.
(e) A solution of HCl gas in water conducts electricity because _____, but a solution of HCl gas in toluene does not conduct an electric current because_____.
(f) Pure water consists entirely of ………….. (ions/molecules).
(g) We can expect that pure water …………… (will/will not) normally conduct electricity.
(h) Electrolysis is the passage of……………. (electricity/electrons) through a liquid or a solution accompanied by a ………….. (physical/chemical) change.
Ans:
(a) Powdered sodium chloride (common salt) does not conduct an electric current, but it does so when dissolved in water or when melted.
(b) Molten lead bromide conducts electricity .It is called an electrolyte. It is composed of lead ions and bromide ions. The lead ions are positively charged and are called cations. The bromide ions are negatively charged and are called anions.
(c) Substances which conduct electricity in the solid state are generally metals.
(d) The electron releasing tendency of zinc is more than that of copper.
(e) A solution of HCl gas in water conducts electricity because it ionizes , but a solution of HCl gas in toluene does not conduct an electric current because it does not ionize in toluene.
(f) Pure water consists entirely of molecules.
(g) We can expect that pure water will not normally conduct electricity.
(h) Electrolysis is the passage of electricity through a liquid or a solution accompanied by a chemical change.
Que-2: Define the following terms:
(a) Electrolysis
(b) Non-electrolyte
(c) Cation and an anion
(d) Weak electrolyte
Ans:
(a) Electrolysis: It is the process of decomposition of a chemical compound in aqueous solutions or in molten state accompanied by a chemical change using direct electric current.
(b) Non-electrolyte: It is a compound which neither in solution nor in the molten state allows an electric current to pass through it.
(c) Cation and anion: Atoms which carry positive charge are called cations.
Atoms which carry negative charge are called anions.
(d) Weak electrolyte: Electrolytes which allow small amount of electricity to flow through them and are partially dissociated in fused or aqueous solution are called weak electrolyte.
Que-3: What is the difference between:
(a) Modern explanation and Arrhenius explanation for the theory of electrolysis
(b) Electrolytic dissociation and ionization
(c) A cation and an anion
(d) Electrolytic dissociation and thermal dissociation
(e) Strong electrolyte and weak electrolyte
Ans:
(a) Difference between Modern explanation and Arrhenius explanation for the theory of electrolysis:
Arrhenius considered that water ionizes electrolytes but Modern theory explained that electrolytes are ionic even in solid state and their ions are held by strong electrostatic forces which make them immobile. Water renders these ions mobility by breaking the electrostatic forces.
(b) Difference between electrolytic dissociation and ionization :
| Ionisation | Dissociation |
| 1. Formation of positively or negatively charged ions from molecules which are not initially in the ionic state. | 1. Separation of ions which are already present in an ionic compound. |
| 2. Polar covalent compounds show ionization. e.g. HCl, H2CO3, NH4OH etc. | 1. Electrovalent compounds show dissociation. e.g. Potassium chloride , lead bromide, etc. |
(c) difference between A cation and anion:
| Cation | Anion |
| 1. Are positively charged ions. | Are negatively charged ions. |
| 2. Migrate to cathode during electrolysis. | Migrate to anode during electrolysis. |
| 3. Gain electron from the cathode and get reduced to become a neutral atom. | Lose electrons to the anode and get oxidized to become a neutral atom. |
(d) difference between Electrolytic dissociation and thermal dissociation:
Electrolytic dissociation is the dissociation of an electrovalent compound into ions in the fused state or in aqueous solution state.
Thermal dissociation: Reversible breakdown of a chemical compound into simpler substances by heating it. The splitting of ammonium chloride into ammonia and hydrogen chloride is an example. On cooling, they recombine to form the salt.
(e) difference between Strong Electrolytes and Weak Electrolytes.
| Strong Electrolytes | Weak Electrolytes |
| Electrolytes which allow a large amount of electricity to flow through them. | Electrolytes which allow small amounts of electricity to flow through them. |
| These are good conductors of electricity. | These are poor conductors of electricity. |
| These almost completely dissociate in the fused or aqueous solution state. | These are partially dissociated in the fused or aqueous solution state. |
| These solutions contain only free mobile ions. | These solutions contain ions as well as molecules. |
Que-4: Name:
(a) A salt which is a weak electrolyte
(b) A base which is a weak electrolyte
(c) An inert electrode and an active electrode
(d) A positively charged non-metallic ion
(e) The electrode at which reduction occurs
(f) A non-metallic element which is a conductor of electricity
Ans:
(a) Sodium carbonate
(b) NH4OH
(c) An inert electrode: graphite and Active electrode: silver
(d) H+
(e) Electrode is cathode
(f) Graphite
Que-5: Electrolysis is a redox process. Explain.
Ans:
Electrolysis is a redox process. The reaction at the cathode involves reduction of cations as they gain of electrons while the reaction at anode involves oxidation of anions as they loss of electrons to become neutral.
Example: Dissociation of sodium chloride during electrolysis.
NaCl Na+ + Cl–
Cathode : Na+ + e- Na(reduction)
Cl– – e– Cl(oxidation)
Cl + Cl Cl2
Overall reaction :2NaCl 2Na + Cl2
Que-6: Classify the following substances under three headings:
(a) strong electrolytes
(b) weak electrolytes
(c) non-electrolytes
Acetic acid, ammonium chloride, ammonium hydroxide, carbon tetrachloride, dilute hydrochloric acid, sodium acetate, dilute sulphuric acid.
Ans:
(a) dilute hydrochloric acid, dilute sulphuric acid, sodium acetate
(b) acetic acid, ammonium hydroxide
(c) carbon tetrachloride
Que-7: Explain why:
(a) Cu, though a good conductor of electricity, is a non-electrolyte.
(b) Solid sodium chloride does not allow electricity to pass through.
Ans:
(a) Copper metal is a solid and has no mobile ions, whereas an electrolyte should dissociate into oppositely charged ions to conduct the electric current.
(b) In solid sodium chloride, Na+and Cl– ions are not mobile to conduct the electric current.
Que-8: Choose A, B, C or D to match the descriptions
(i) to (v) below. Some letters may be repeated.
(A) non-electrolyte (B) strong electrolyte (C) weak electrolyte (D) metallic conductor
(i) Molten ionic compound
(ii) Carbon tetrachloride
(iii). An aluminium wire
(iv) A solution containing solvent molecules, solute molecules and ions formed by the dissociation of solute molecules.
(v) A sugar solution with sugar molecules and water molecules.
Ans:
(i) Molten ionic compound – strong electrolyte
(ii) Carbon tetrachloride – non-electrolyte
(iii). Aluminium wire – metallic conductor
(iv) A solution containing solvent molecules, solute molecules and ions formed by the dissociation of solute molecules. – weak electrolyte
(v) A sugar solution with sugar molecules and water molecules. – non-electrolyte
Que-9: An electrolyte which complete dissociate into ions is:
(A) Alcohol (B) Carbonic Acid (C) sucrose (D) Sodium Hydroxide
Ans:
Option (D) Sodium Hydroxide is correct
—: End of Electrolysis Intex-1 Concise Class-10 ICSE Chemistry Selina Solutions : –
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