Class 10 Chemistry Chapter 5 Important Questions with Answers Kerala Syllabus

Students rely on Class 10 Chemistry Notes Kerala Syllabus Chapter 5 Important Questions with Answers Electrochemistry to help self-study at home.

SSLC Chemistry Chapter 5 Important Questions Kerala Syllabus

Electrochemistry Class 10 Important Questions

Question 1.
Which substance is deposited at the cathode when aqueous Sodium Chloride is electrolysed? [Oxygen, Chlorine, Sodium, Hydrogen]
Answer:
Hydrogen

Question 2.
In the process of electroplating copper on an iron bangle, the bangle is connected to which terminal of the battery?
Answer:
Negative terminal

Question 3.
Statement 1: A Galvanic cell is an electrochemical cell that converts chemical energy into electrical energy.
Statement 2: A galvanic cell requires an external power source to function.
Which of the following is correct regarding the above statements?
A. Both statements are correct
B. Both statements are not correct
C. Only statement 1 is correct
D. Only statement 2 is correct
Answer:
C. Only statement 1 is correct
Galvanic cells generate electrical energy spontaneously and do not require an external power source

Question 4.
a) Which of the following metals reacts vigorously with diluted hydrochloric acid?
a) Gold
b) Magnesium
c) Lead
d) Iron
Answer:
b) Magnesium

Question 5.
Match the following.

Column A	Column B
1. Primary Cells	a) Can be recharged and used again.
2. Secondary Cells	b) Cannot be recharged.
3. Fuel Cells	c) Convert chemical energy into electrical energy by the combustion of fuel.

Choose the correct answer from the options given below.
a) 1 – b, 2 – a, 3 – c
b) 1 – c, 2 – a, 3 – b
c) 1 – a, 2 – c, 3 – b
d) 1 – c, 2 – a, 3 – b
Answer:
a) 1 – b, 2 – a, 3 – c

Column A	Column B
1. Primary Cells	b) Cannot be recharged.
2. Secondary Cells	a) Can be recharged and used again.
3. Fuel Cells	c) Convert chemical energy into electrical energy by the combustion of fuel.

Question 6.
Find out whether the following statements are true or false. If false, correct the statement.
I. Oxidation takes place at the cathode in the galvanic cell.
II. Electrical energy is converted into chemical energy in an electrolytic cell.
III. Electrical energy is converted into chemical energy in a galvanic cell.
Answer:
I) False – Oxidation takes place at the anode in a galvanic cell.
II) True
III) False – Chemical energy is converted into electrical energy.

Question 7.
a) In which test tube displacement reaction take place

b) Why doesn’t the displacement reaction take place in one of the test tubes?
Answer:
a) Test tube 1
b) In the second test tube, Ag is less reactive than copper. So, a displacement reaction cannot occur.

Question 8.
Copper is electroplated on an iron ring.
a) Which electrolyte is used here?
b) Which metal is connected to the positive terminal of the battery?
Answer:
a) Copper sulphate solution
b) Cu

Question 9.
Name the electrolytes used for the electrolysis of copper, silver and gold.
Answer:

Metals to be covered	Electrolyte
Copper	Copper sulphate
Silver	Silver nitrate (or) Sodium cyanide + Silver cyanide solution
Gold	Sodium cyanide + Gold Cyanide solution

Question 10.
A student draws the arrangement of a galvanic cell as shown below. Find out if there is any mistake? If so, draw the correct picture of the galvanic cell.

Answer:

Each metal should be placed in its own salt solution; that is, the Zn rod should be dipped in ZnSO₄, and the Cu rod should be dipped in CuSO₄.If the arrangement is correct, electron flow is from Zinc to copper.

Question 11.
a) Which is the anode and cathode in the Mg – Ag galvanic cell?
b) Write the reaction taking place at anode and cathode of this cell.
c) Write the equation of a redox reaction.
Answer:
a) Anode – Mg, Cathode – Ag

b) Anodic reaction: Mg → Mg²⁺ + 2e^–
Cathodic reaction: 2Ag⁺ + 2e^– → 2Ag

c) Redox reaction: Mg + 2Ag⁺ → Mg²⁺ + 2Ag

Question 12.
Observe the figure in which a copper plate is immersed in AgNO₃ (Silver Nitrate) solution. (Reactivity: Cu > Ag)

a) The reaction taking place here is a redox reaction. Why?
b) What change can be observed on the copper plate?
c) Write the equation of the oxidation reaction taking place here.
Answer:
a) Oxidation and reduction take place simultaneous!}’, so this reaction is a redox reaction.
b) A layer of Ag is deposited on the Copper plate, and the silver nitrate solution turns blue.
c) Cu → Cu²⁺ + 2e^–

Question 13.
A galvanic cell is constructed using Mg and Cu as electrodes.
a) What is the energy change taking place in a galvanic cell?
b) Which is the anode of the given galvanic cell?
c) Write the equation of the chemical reaction taking place at the cathode.
Answer:
a) Chemical energy is converted into electrical energy.
b) Mg
c) Cu²⁺ + 2e^– → Cu

Question 14.
The figure given below represents metals like Fe, Cu, and Mg kept in dilute HCl

a) Which among these test tubes didn’t show any reaction? Which metal was kept in that test tube?
b) Which metal is present in test tube 1? Give an equation for this reaction.
c) Arrange the given metals in the increasing order of their reactivity towards acids.
Answer:
a) 3^rd test tube, Cu

b) Mg. Because Mg reacts vigorously with HCl, more H₂ gas is produced.
Mg + 2HCl → MgCl₂ + H₂
c) Mg > Fe > Cu

Question 15.
Analyse the picture of an experiment.
a) What change took place on the surface of the iron nail?

b) Which among the following reactions are involved in the above change?
Fe²⁺ + 2 e^– → Fe
Ag⁺ + 1 e^– → Ag
Fe → Fe²⁺ + 2e^–
Ag → Ag⁺ + 1 e^–

c) Which is oxidised? Which is reduced?
Answer:
a) Ag is deposited on the nail.
b) Fe → Fe²⁺ + 2e^–
Ag⁺ + 1 e^– → Ag
c) Fe is oxidised, Ag⁺ is reduced.

Question 16.
Some materials are given below:

a) From the given materials, choose the appropriate ones to constmct a galvanic cell and draw the diagram of the cell. (Order of reactivity: Mg > Fe > Cu > Ag)
b) Which is the anode of this cell?
c) At which electrode does reduction take place?
d) Write the chemical equation of the reaction taking place at the cathode.
Answer:
a) Mg, MgSO₄, Cu, CuSO₄, Salt bridge, connecting wire with voltmeter connected.

b) Mg/Magnesium
c) Cathode (Cu rod)
d) Cu²⁺ + 2e^– → Cu

Question 17.
The zinc rod is dipped in CuSO₄ solution. Observe the changes taking place after some time.
a) Which metal is more reactive, Zn or Cu?
b) Which metal is displaced during this reaction?
c) Is this a redox reaction? Give reason.
Answer:
a) Zn

b) Cu

c) Yes. Here, Zn gets oxidised, and Cu is reduced. Thus, both oxidation and reduction take place simultaneously. So, this is a redox reaction.

Question 18.
Analyse the picture of an experiment.

a) What is the reason for the decrease in the green colour of the FeSO₄ solution?
b) The equation for this reaction is given below. Complete it.
Zn + FeSO₄ → ……… + ZnSO₄
c) If Pb is used instead of Zn, no reaction takes place. From this, what inference regarding the reactivity of lead can be obtained?
Answer:
a) Zn displaces iron from the FeSO₄ solution.
b) Zn + FeSO₄ → Fe + ZnSO₄
c) Pb is less reactive than Zn.

Question 19.
Observe the pictures given below. Based on the reactivity series, predict which of these undergoes a displacement reaction. Complete the table.

Metal	Solution	Displacement reaction
Mg	CuSO4	(a)
Ag	CuSO4	(b)
Mg	ZnSO4	Takes place
Mg	AgNO3	(c)
Cu	MgSO4	(d)

Answer:
a) Takes place
b) Does not take place
c) Takes place
d) Does not take place

Question 20.
a) Draw a diagram of the setup for electroplating gold onto a copper bangle and label its parts.
b) What are the advantages of electroplating?
c) A picture of the arrangement of copper plating on an iron bangle is given below. What are the mistakes in this?

Answer:
a)

b)

• It enhances the beauty of metal
• Prevents corrosion

c) Copper should be connected to the positive terminal of the battery.
The iron bangle should be connected to the negative terminal of the battery.
Copper sulfate solution should be used as the electrolyte.