Predict the products of electrolysis in | Class 12 Chemistry Chapter Electrochemistry, Electrochemistry NCERT Solutions

Welcome to the NCERT Solutions for Class 12 Chemistry - Chapter Electrochemistry. This page offers a step-by-step solution to the specific question from Exercise 2, Question 18: . 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.

Question 18:

Predict the products of electrolysis in each of the following:

(i) An aqueous solution of AgNO₃ with silver electrodes.

(ii) An aqueous solution of AgNO₃with platinum electrodes.

(iii) A dilute solution of H₂SO₄with platinum electrodes.

(iv) An aqueous solution of CuCl₂ with platinum electrodes.

Answer:

(i) At cathode: The following reduction reactions compete to take place at the cathode.

The reaction with a higher value of E^º takes place at the cathode. Therefore, deposition of silver will take place at the cathode.

At anode:

The Ag anode is attacked by NO₃^-ions. Therefore, the silver electrode at the anode dissolves in the solution to form Ag+.

(ii) At cathode:

The following reduction reactions compete to take place at the cathode.

The reaction with a higher value of E^ºtakes place at the cathode. Therefore, deposition of silver will take place at the cathode.

At anode:

Since Pt electrodes are inert, the anode is not attacked by NO₃^-ions. Therefore, OH^-or NO₃^-ions can be oxidized at the anode. But OH^-ions having a lower discharge potential and get preference and decompose to liberate O₂.

OH^-→ OH + e^-

4OH^- → 2H₂O +O₂

(iii) At the cathode, the following reduction reaction occurs to produce H₂ gas.

H⁺ _(aq) + e^- → ½ H_2(g)

At the anode, the following processes are possible.

For dilute sulphuric acid, reaction (i) is preferred to produce O₂ gas. But for concentrated sulphuric acid, reaction (ii) occurs.

(iv) At cathode:

The following reduction reactions compete to take place at the cathode.

The reaction with a higher value of E^ºtakes place at the cathode. Therefore, deposition of copper will take place at the cathode.

At anode:

The following oxidation reactions are possible at the anode.

At the anode, the reaction with a lower value of E^ºis preferred. But due to the over-potential of oxygen, Cl^- gets oxidized at the anode to produce Cl₂ gas.

Other Questions of Chapter Electrochemistry

The resistance of a conductivity cell containing 0.001M KCl solution at 298 K is 1500 Ω. What is the cell constant if conductivity of 0.001M KCl solution at 298 K is 0.146 x 10^-3S cm^-1.

Can you store copper sulphate solutions in a zinc pot?

How much electricity is required in coulomb for the oxidation of

(i) 1 mol of H₂O to O₂.

(ii) 1 mol of FeO to Fe₂O₃.

If a current of 0.5 ampere flows through a metallic wire for 2 hours, then how many electrons would flow through the wire?

A solution of Ni(NO₃)₂ is electrolysed between platinum electrodes using a current of 5 amperes for 20 minutes. What mass of Ni is deposited at the cathode?

Calculate the potential of hydrogen electrode in contact with a solution whose pH is 10.

Arrange the following metals in the order in which they displace each other from the solution of their salts.

Al, Cu, Fe, Mg and Zn

Explain how rusting of iron is envisaged as setting up of an electrochemical cell.

In the button cells widely used in watches and other devices the following reaction takes place:

Zn(s) + Ag₂O(s) + H₂O(l) → Zn²⁺(aq) + 2Ag(s) + 2OH ^- (aq)

Determine and for the reaction.

Suggest a list of metals that are extracted electrolytically.

Popular questions of class 12 Chemistry

How the following conversions can be carried out?

(i) Propene to propan-1-ol

(ii) Ethanol to but-1-yne

(iii) 1-Bromopropane to 2-bromopropane

(iv) Toluene to benzyl alcohol

(v) Benzene to 4-bromonitrobenzene

(vi) Benzyl alcohol to 2-phenylethanoic acid

(vii) Ethanol to propanenitrile

(viii) Aniline to chlorobenzene

(ix) 2-Chlorobutane to 3, 4-dimethylhexane

(x) 2-Methyl-1-propene to 2-chloro-2-methylpropane

(xi) Ethyl chloride to propanoic acid

(xii) But-1-ene to n-butyliodide

(xiii) 2-Chloropropane to 1-propanol

(xiv) Isopropyl alcohol to iodoform

(xv) Chlorobenzene to p-nitrophenol

(xvi) 2-Bromopropane to 1-bromopropane

(xvii) Chloroethane to butane

(xviii) Benzene to diphenyl

(xix) tert-Butyl bromide to isobutyl bromide

(xx) Aniline to phenylisocyanide

Give simple chemical tests to distinguish between the following pairs of compounds.

(i) Propanal and Propanone

(ii) Acetophenone and Benzophenone

(iii) Phenol and Benzoic acid

(iv) Benzoic acid and Ethyl benzoate

(v) Pentan-2-one and Pentan-3-one

(vi) Benzaldehyde and Acetophenone

(vii) Ethanal and Propanal

A 5% solution (by mass) of cane sugar in water has freezing point of 271 K. Calculate the freezing point of 5% glucose in water if freezing point of pure water is 273.15 K.

A solution of glucose in water is labelled as 10% w/w, what would be the molality and mole fraction of each component in the solution? If the density of solution is 1.2 g mL^-1, then what shall be the molarity of the solution?

Henry's law constant for CO₂ in water is 1.67 x 10⁸Pa at 298 K. Calculate the quantity of CO₂in 500 mL of soda water when packed under 2.5 atm CO₂pressure at 298 K.

Calculate the mass of a non-volatile solute (molar mass 40 g mol^-1) which should be dissolved in 114 g octane to reduce its vapour pressure to 80%.

The vapour pressure of pure liquids A and B are 450 and 700 mm Hg respectively, at 350 K. Find out the composition of the liquid mixture if total vapour pressure is 600 mm Hg. Also find the composition of the vapour phase.

Calculate the mole fraction of benzene in solution containing 30% by mass in carbon tetrachloride.

How many mL of 0.1 M HCl are required to react completely with 1 g mixture of Na₂CO₃ and NaHCO₃ containing equimolar amounts of both?

If NaCl is doped with 10^-3mol % of SrCl₂, what is the concentration of cation vacancies?

Recently Viewed Questions of Class 12 Chemistry

Henry's law constant for CO₂ in water is 1.67 x 10⁸Pa at 298 K. Calculate the quantity of CO₂in 500 mL of soda water when packed under 2.5 atm CO₂pressure at 298 K.

What are nucleic acids? Mention their two important functions.

What are the different oxidation states exhibited by the lanthanoids?

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}

Mention the conditions required to maximise the yield of ammonia.

Ionic solids conduct electricity in molten state but not in solid state. Explain.

Describe the oxidising action of potassium dichromate and write the ionicequations for its reaction with:

(i) iodide

(ii) iron

(II) solution and

(iii) H₂S

What type of solids are electrical conductors, malleable and ductile?

Write the structure of the major organic product in each of the following reactions:

Ferric oxide crystallises in a hexagonal close-packed array of oxide ions with two out of every three octahedral holes occupied by ferric ions. Derive the formula of the ferric oxide.

Study Tips for Answering NCERT Questions:

NCERT questions are designed to test your understanding of the concepts and theories discussed in the chapter. Here are some tips to help you answer NCERT questions effectively:

Read the question carefully and focus on the core concept being asked.
Reference examples and data from the chapter when answering questions about Electrochemistry.
Review previous year question papers to get an idea of how such questions may be framed in exams.
Practice answering questions within the time limit to improve your speed and accuracy.
Discuss your answers with your teachers or peers to get feedback and improve your understanding.

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Comments

Megha
Sep 17, 2019

Last part is not clear

KRISHAN KUMAR
May 12, 2019

Pt has higher srep still it is not reduced in cathode why?

KRISHAN KUMAR
May 12, 2019

Thank you have a nice day

pratik
Sep 21, 2018

i am not getting it