Lakhmir Singh solutions for केमिस्ट्री [अंग्रेजी] कक्षा १० आईसीएसई chapter 6 - Electrolysis [Latest edition]

State whether the following statement is True or False.

Non-electrolytes conduct electricity in a solid state.

State whether the following statement is True or False.

Electrochemical cell converts chemical energy into electrical energy.

State whether the following statement is True or False.

The anode is connected to negative pole of the battery.

State whether the following statement is True or False.

Reduction is removal of oxygen from a substance.

Aqueous solution of electrolytes contains ______ and ______.

Electrolytic cell converts ______ energy into ______ energy.

Glucose is an example of ______.

The flow of current through electrolyte is due to movement of ______.

Chemical process which involves addition of oxygen is ______.

Hydrogen sulphide is an example of ______.

Metal and alloys are ______ of electricity.

Define electrodes.

Give two examples of reducing agents.

Give two examples of oxidising agents.

What is meant by the term ‘electrolyte’?

What are non-electrolytes?

Differentiate between electrochemical and electrolytic cells.

Name a salt which is a weak electrolyte.

What is the difference between metallic and electrolytic conductors?

Give an example of a reaction where hydrogen sulphide behaves as reducing agent.

What are strong electrolytes? Give example.

What are weak electrolytes? Give examples.

Define oxidation with an example and the reactions involved.

State whether the following statement is True or False.

Ions are responsible for current flow through the solution.

State whether the following statement is True or False.

Hydrogen gas and metals are liberated at the anode.

State whether the following statement is True or False.

Sodium chloride is a covalent compound.

State whether the following statement is True or False.

HCl can conduct electricity in a pure liquid state.

H⁺ combines with water to form ______.

Electrolysis is a ______ reaction.

The extent to which an electrolyte can dissociate is called ______.

Non-metals are liberated at ______.

The mass of substance produced at an electrode during electrolysis is proportional to ______.

Following are example of covalent compounds:

Electrovalent compounds are held together by ______.

Write two examples of polar covalent compounds that conduct electricity.

Define electrolytic dissociation.

Write postulates of electrolytic dissociation theory.

What is the difference between:

Electrolytic dissociation and ionisation.

Explain electrolytic dissociation of sodium chloride.

Write four characteristics of electrolysis.

Electrolysis is a redox process. Explain.

Daniel cell is an electrochemical cell, which converts chemical energy into electrical energy. With the help of the internet find what electrodes and electrolytes are used in the Daniel cell. Prepare a presentation on its working. Figure out what could be the possible reactions taking place at the cathode and anode.

State whether the following statement is True or False.

Sodium is converted into Na⁺ ion easily compared to copper to Cu²⁺.

State whether the following statement is True or False.

During electrolysis of molten lead bromide, bromine evolves at the cathode.

State whether the following statement is True or False.

Lower is the position of an anion in the series, more difficult is to get discharged at the anode.

State whether the following statement is True or False.

The oxidation of non-metals always occurs at the anode during electrolysis.

Cu, Ni are examples of ______ electrodes.

Electrolysis of water gives ______ volume of hydrogen and ______ volume of oxygen.

During electrolysis of copper sulphate solution, ______ is deposited at the cathode.

The most reactive metal is ______.

Which of the following is correct regarding the electrolysis of concentrated NaCl solution?

In copper sulphate solution, the total number of types of ions present is ______.

In the electrolysis of lead bromide, the electrode used is made of ______.

What is the electrochemical series?

Which is the most reactive metal in the electrochemical series?

Which is the least reactive metal in the electrochemical series?

On what factors does selective discharge of ions depend?

Why nitric acid is not added for acidifying water during electrolysis?

What is the ratio of oxygen to hydrogen formed during electrolysis of water? Explain.

Write the reaction occurring at the cathode during electrolysis of acidified water.

Write the reaction occurring at the anode during electrolysis of acidified water.

Give the reaction occurring at the cathode during electrolysis of molten lead bromide.

List characteristics of the electrochemical series of metals.

Explain the electrolysis of copper sulphate solution using a platinum anode and a copper cathode.

State whether the following statement is True or False.

Brass objects are generally plated with silver to give them an attractive look.

State whether the following statement is True or False.

Nickel sulphite solution is used for electroplating iron objects with nickel.

State whether the following statement is True or False.

In electrorefining of copper, a pure block of copper is used as an anode.

State whether the following statement is True or False.

For extraction of calcium, molten calcium chloride is used as an electrolyte.

The article to be electroplated is always placed at ______.

On electro-refining of copper, ______ is formed at the anode.

For electroplating ______ current is used.

The following are the application of electrolysis:

Electrode used for electrometallurgy of metals is ______.

During electro-refining of copper:

During electroplating of iron using silver, anode is made of ______.

Give three applications of electrolysis.

Why is electroplating done?

Give three conditions for electroplating.

How is smooth and firm electroplating obtained?

What do you understand by the term electro-refining?

What do you understand by the term electro-metallurgy?

Give the reactions involved in electroplating of iron using silver.

What are the electrodes, electrolyte used in electrolytic refining of copper?

Give the reactions occurring at cathode and anode during electrolytic refining of copper.

How is calcium extracted through electrometallurgy? Give the reactions involved.

How is aluminium extracted through electrometallurgy? Give the reactions involved.

True or False.

Electrodes used in the process of electrolysis are always inert.

True or False.

Metals present below hydrogen can displace hydrogen atoms from acids, while those above it cannot.

True or False.

Electrolysis of copper sulphate solution takes place at room temperature.

True or False.

Metals which are present at a lower position in the electrochemical series are extracted using electrolysis.

True or False.

Electrolytes cannot be dissociated even in the molten or aqueous state.

Extraction of metals using electrolysis is called ______.

The process by which covalent compounds are converted into ions in water solution is known as ______.

The cathode is the electrode which is connected to ______ pole of the battery.

In the reaction \[\ce{C + ZnO -> Zn + CO}\], carbon is ______ agent.

Electroplating of metal is depositing a thin film of ______ metal on ______ metal.

Which of the following is non-electrolyte?

Oxidation is:

Which of the following is least reactive?

The factor which effects the selective discharge of ions is:

In the electrolysis of molten lead bromide, an electrolytic cell is made of ______.

The article to be electroplated is placed at ______.

During extraction of potassium, potassium is formed at ______.

During electro-refining of copper, at the anode ______.

For electrolysis of copper sulphate solution:

Electroplating is done to ______.

During electrolysis of acidified water, ______.

Match the following columns and choose the correct answer.

Match the following columns and choose the correct answer.

Identify one statement that holds true for electrolysis of molten lead bromide:

Solid sodium chloride does not conduct electricity as ______.

If a solution of an electrolyte mixture has calcium ions, cupric ions, zinc ions and magnesium ions, which of these ions would you see preferentially discharged at the cathode?

Which of the following ions will readily discharge at the anode during the electrolysis of acidified water?

Which statement about conduction of electricity is correct?

In the circuit below, the lamp lights up.

What could X be?

The oxidation reaction among the following is:

Which apparatus could be used to electroplate an iron nail with copper?

Identify the following reactions as either oxidation or reduction : O + 2e^- → O^-2

Identify the following reactions as either oxidation or reduction : K - e^- → K⁺

Identify the following reactions as either oxidation or reduction : Fe⁺³ + e^-  → Fe⁺²

Aqueous solution of nickel sulphate contains \[\ce{Ni^{+2}}\] and \[\ce{SO^{-2}_{4}}\] ions.

1. Which ion moves towards the cathode?
2. What is the product at the anode?

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

During the electrolysis of copper (II) sulphate solution using platinum as cathode and carbon as anode:

1. What do you observe at the cathode and at the anode?
2. What change is noticed in the electrolyte?
3. Write the reactions at the cathode and at the anode.

The following questions relate to the extraction of aluminium by electrolysis.
Name the other aluminium containing compound added to alumina and state the significance.

The following question relate to the extraction of aluminium by electrolysis.

Give the equation for the reaction that takes place at the cathode.

The following questions relate to the extraction of aluminium by electrolysis.
Explain why it is necessary to renew the anode periodically.

Why do covalent compounds exist as gases, liquids or soft solids?

Which electrode—anode or cathode—is the oxidising electrode? Why?

Differentiate between the terms strong electrolyte and weak electrolyte (stating any two differences)

Copy and complete the following table :

 Write the equation taking place at the anode.

Name the product formed at the anode during the electrolysis of acidified water using platinum electrodes

Name the metallic ions that should be present in the electrolyte when an article made copper is to be electroplated with silver

Give reasons why sodium chloride will conduct electricity only in the fused or aqueous solution state.

Give reasons why in the electroplating of an article with silver, the electrolyte sodium argentocynide solution is preferred over silver nitrate solution.

Give reasons why although copper is a good conductor of electricity, it is a non-electrolyte.

Write equations for the reactions taking place at the two electrodes (mentioning clearly the name of the electrode) during the electrolysis of acidified copper sulphate solution with copper electrodes.

Write equations for the reactions taking place at the two electrodes (mentioning clearly the name of the electrode) during the electrolysis of molten lead bromide with inert electrodes.

Select the ion in the following case, that would get selectively discharged from the aqueous mixture of the ions listed below:

\[\ce{SO^2-_4, NO^-_3 {and} OH-}\]

Select the ion in the following case, that would get selectively discharged from the aqueous mixture of the ions listed below:

Pb²⁺, Ag⁺ and Cu²⁺

State the observation at the anode and at the cathode during the electrolysis of :
Fused lead bromide using graphite electrodes

State the observation at the anode and at the cathode during the electrolysis of :
Copper sulphate solution using copper electrodes.

Copy and complete the following table which refers to the conversion of ions to neutral particles.

 Name the gas evolved in each of the following cases : 
Alumina undergoes electrolytic reduction.

 Name the gas evolved in each of the following cases :
Ethene undergoes hydrogenation reaction. 

Name the gas evolved in each of the following cases :
Ammonia reacts with heated copper oxide.

Differentiate between the following pair based on the information given in the bracket.

Conductor and electrolyte (conducting particles)

Differentiate between the following pair based on the information given in the bracket.

Cation and anions (formation from an atom)

Differentiate between the following pair based on the information given in the bracket.

Acid and Alkali (formation of type of ions)

 Name the particles present in : 
Strong electrolyte 

Name the particles present in non-electrolyte.

 Name the particles present in :
 Weak electrolyte 

Identify the substance underlined in the following:

The electrode that increases in mass during the electrorefining of silver.

Identify the substance underlined in the following:

The acid that is a dehydrating as well as a drying agent.

Identify the substance underlined in the following:

The catalyst used to oxidise ammonia into nitric oxide.

Choose the correct word which refers to the process of electrolysis from A to E to match the description (a) to (d):

A: Oxidation B: Cathode C: Anode D: An electrolyte E: Reduction

1. Conducts electricity in aqueous or in molten state.
2. Loss of electron takes place at anode.
3. A reducing electrode.
4. Electrode connected to the positive end or terminal of the battery.

An aqueous solution of nickel (II) sulphate was electrolysed using nickel electrodes. Observe the diagram and answer the questions that follow:

1. What do you observe at the cathode and anode respectively?
2. Name the cation that remains as a spectator ion in the solution.
3. Which equation for the reaction at the anode is correct?
   1. \[\ce{Ni -> Ni^{2+} + 2e-}\]
   2. \[\ce{Ni + 2e- -> Ni^{2+}}\]
   3. \[\ce{Ni^{2+} -> Ni + 2e-}\]
   4. \[\ce{Ni^{2+} + 2e- -> Ni}\]

Study the diagram given alongside and answer the questions that follow :

(i) Give the names of the electrode A and B.
(ii) Which electrode is oxidizing electrode?

A strip of copper is placed in four different colourless salt solutions. They are KNO₃, AgNO₃, Zn(NO₃)₂ and Ca(NO₃)₂. Which one of the solutions will finally turn blue?

Write the equations of the reactions which take place at the cathode and anode when acidified water is electrolyzed.

Choose A, B, C or D to match the descriptions (i) to (v) below . Some alphabets 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.

The following is a sketch of an electrolytic cell used in the extraction of aluminium :

(a) What is the substance of which the electrode A and B are made?
(b) At which electrode (A or B) is aluminium formed?
(c) What are the two aluminium compounds in the electrolyte C?
(d) Why is it necessary for electrode B to be continuously replaced?

A metal article is to be electroplated with silver. The electrolyte selected is sodium argentocyanide.

1. What kind of salt is sodium argentocyanide?
2. Why is it preferred to silver nitrate as an electrolyte?
3. State one condition to ensure that the deposit is smooth, firm and long lasting.
4. Write the reaction taking place at the cathode.
5. Write the reaction taking place at the anode.
   

Mr Ramu wants electrolyte his key chain with nickel to prevent rusting. For this electroplating
(i) Name the electrolyte
(ii) Name the cathode
(iii) Name the anode
(iv) Give the reaction at the cathode
(v) Give the reaction at the anode

An aqueous electrolyte consists of the ions mentioned in the list. The ion which could be discharged most readily during electrolysis.

The metallic electrode which does not take part in an electrolytic reaction.

The ion which is discharged at the cathode during the electrolysis of copper sulphate solutions using copper electrodes as an anode and cathode.

When dilute sodium chloride is electrolysed using graphite electrodes, the cation which is discharged at the cathode most readily.

During silver plating of an article using potassium argentocyanide as an electrolyte, the anode material should be.

Copper sulphate solution is electrolyzed using copper electrodes. Study the diagram given alongside and answer the questions that follow.

1. Which electrode to your left or right is known as the oxidizing electrode and why?
2. Write the equation representing the reaction that occurs.
3. State two appropriate observations for the above electrolysis reactions.

M is a metal above hydrogen in the activity series and its oxide has the formula M₂O. The oxide when dissolved in water forms the corresponding hydroxide which is a good conductor of electricity. In the above context answer the following:

1. What kind of combination exists between M and O?
2. How many electrons are there in the outermost shell of M?
3. Name the group to which M belongs.
4. State the reaction taking place at the cathode.
5. Name the product at the anode.