Xam Idea Class 12 Chemistry Chapter 3 Solutions: Electrochemistry

Xam Idea Class 12 Chemistry Solutions Chapter 3 – Electrochemistry is provided here to help you understand all the ideas of electrochemistry clearly and develop a strong base of the electrochemistry topic. These solutions follow the guidelines given by CBSE. Our solutions have been prepared by eminent  Chemistry experts. They are the best material to refer to if you want to perform excellently well in the exams and pursue your desired course after Class 12.

Part A of Xam idea class 12 Chemistry Solutions contains the explanation for all fundamental concepts contained in the chapter and a variety of questions. The questions are based on memory, and higher-order thinking skills and are divided into the very short answer questions, short answer type questions and long answer type question. Part B of our solutions contains elaborated solutions to questions papers based on the CBSE format to give you ample exam pattern practice.

Chapter 3 is about electrochemical cells, galvanic cells and measurement of electrode potential, Nernst equation, determining equilibrium constant from Nernst equation, electrochemical cell, Gibbs energy of reaction, the conductance of electrolytic solutions, measurement of the conductivity of ionic solutions, the variation of conductivity and molar conductivity with concentration. Here you also get to know about electrolytic cells and electrolysis, products of electrolysis, batteries, primary batteries, secondary batteries, fuel cells and the phenomenon of corrosion and how it is related to the formation of localized cells on metal surfaces.

Xam Idea Class 12 Chemistry Chapter 3 Overview

Our Xam Idea Class 12 Chemistry Chapter 3-Electrochemistry  cover all the concepts given in the unit. They enable you to delve deep into the concepts taught in this chapter. The outline of the concepts covered in this chapter has been given below.

  • Electrochemical Cells

This part of the chapter tells you that an electrochemical cell consists of two electrodes and a conducting solution known as an electrolyte. Electrochemical cells are of two types. The first one is the galvanic cell in which chemical energy derived from a spontaneous reaction is converted into electrical work. The second one is the electrolytic cell which utilizes electricity to carry out a non-spontaneous chemical reaction. Our notes and solutions help you learn the basic idea of electrochemical cells in detail.

  • Galvanic Cells

This part of the chapter tells you that the redox chemical reactions can be divided into oxidation half and reduction half-reactions. The oxidation half takes place at the anode, and the reduction half occurs at the cathode. Here you will also learn that the potential difference developed between the electrodes is known as electrode potential. The standard electrode potential for any electrode put in a proper solution is defined with respect to standard electrode potential of hydrogen electrode considered as zero. This section also teaches you that the standard potential of a cell is obtained by calculating the difference between electrode potentials of the electrodes of a cell.

  • Nernst Equation

This part of the chapter teaches you about the important Nernst equation. This deals with concentration dependence of the potentials of electrodes and cells. It also helps to determine the equilibrium constant of reactions in equilibrium through the relation – E°cell = E°cell + (RT/nF) ln {[Ox]/[Red]}. This equation is very important from the exam point of view. Our Xam Idea Class 12 Chemistry Solutions Chapter 3-Electrochemistry let you gain the understanding of the correct methodology to answer numerical questions from this section and score good marks in your exams.

  • Electrochemical Cell and Gibbs Energy of a Reaction 
    This portion teaches you about Gibbs energy of an electrochemical reaction and that the reversible work done by a galvanic cell is equal to decrease in its Gibbs energy. The standard potential of the electrical cells is related to standard Gibbs energy (ΔrGθ = -nFEθcell) and equilibrium constant of the reaction occurring in the cell (ΔrGθ = – RT ln K).
  • The conductance of Electrolytic Solutions

This part of the chapter tells you that in case of an electrolytic solution, its conductivity or specific conductance, κ, is dependent upon the concentration of the electrolyte, nature of solvent and temperature. Here you will also learn that the inverse of resistance, R, is called conductance. The specific conductance is expressed in S m-1 and is inverse of resistivity of a solution. Our Xam Idea Class 12 Chemistry Solutions Chapter 3-Electrochemistry make you learn the concept in a faster and efficient way.

  • Measurement of the Conductivity of Ionic Solutions

This part of the chapter tells that measuring the resistance of an ionic solution changes its composition; hence an accurate measurement of resistance of an electrolytic cell is done through a conductivity cell passing AC current. Here you will also learn that the term molar conductivity (Λm) used is related to the conductivity of the solution of concentration c by the equation, Λm = κ/c and takes the units S cm2 mol-1.

  • Variation of Conductivity and Molar Conductivity with Concentration 
    This portion tells you that conductivity is decreased, but molar conductivity is increased when the concentration of a solution is decreased. This is because the number of ions carrying electricity per unit volume decreases on dilution. When concentration becomes almost zero, the molar conductivity of a solution is called limiting molar conductivity (Λ°m). Our comprehensive Xam Idea Class 12 Chemistry Solutions Chapter 3-Electrochemistry explain these concepts well.

Further, you come to know that Λm increases slowly with dilution in case of strong electrolytes as they are highly dissociated into their ions. Kohlrausch law of independent migration of ions implicates that molar conductivity of an electrolyte at infinite dilution is the total of the contribution of the molar conductivity of the ions in which it dissociates. This law finds its application in many places. You further learn here that molar conductivity increases steeply in case of weak electrolytes on increasing dilution of the solution.

  • Electrolytic cells and electrolysis

Here you come to know about electrolysis and its use in metallurgy for commercial production of metals. Further, you come to know about the quantitative aspect of electrolysis which is explained by Faraday’s two laws of electrolysis. The first law relates the amount of chemical reaction happened and current passed in a direct manner and second law states that an equal quantity of electricity would deposit different substances according to their equivalent weights.

It further tells you that charge on one mole of electrons is known as 1 Faraday and is equal to 96487 C. Our Xam Idea Class 12 Chemistry Solutions Chapter 3-Electrochemistry give you an in-depth knowledge of all the concepts helping you in your preparation of Class 12 board exams.

  • Batteries 

This part of the chapter teaches you that batteries are the reservoirs of electrical energy. Batteries convert chemical energy to electrical energy for our consumption. In primary batteries, the reaction occurs only once and, the battery becomes dead after some time. Leclanche cell and mercury cell are common examples of primary batteries. Secondary batteries are recharged on passing external current. Lead storage battery and Ni-Cd cell are common examples here.

  • Fuel Cells

This part of the chapter tells you that producing electricity from thermal plants is a major source of pollution as these plants use fossil fuels for producing energy. You will also learn that fuel cells are galvanic cells designed to convert the energy of combustion of fuels like hydrogen, methane, methanol etc. to electrical energy directly and hence are an alternative source of energy. This important topic has been well covered in this chapter of our Xam Idea  Solutions Chapter 3-Electrochemistry.

  • Corrosion 

Here you learn that corrosion is nothing but an electrochemical phenomenon where metal is oxidized by loss of electrons to oxygen, the formation of oxides takes place. This chapter further talks about methods of prevention of corrosion.

Xam Idea Class 12 Chemistry Chapter 3 – Exercises

After learning all the concepts, you need to solve the questions given in the chapter. The questions types included here are very short answer questions, short answer questions and long answer type questions depending upon their weightage of marks. These questions test your memory skills, analytical skills, understanding of the concepts and higher-order thinking skills. Given below is a summary of the questions in this chapter.

This chapter has 42 VSAQs based on reactivity series, galvanic cell and conductivity, batteries and molar conductivity of the solution. Next, there are 28 SAQs based on the Nernst equation, determination of reaction parameters, conductivity, corrosion, fuel cells and batteries. There are 28 LAQs in this chapter based on Faraday’s law of electrolysis, Galvanic cells, the Nernst equation and fuel cells.

Our Xam Idea Class 12 Chemistry Solutions Chapter 3-Electrochemistry contain stepwise, fully accurate, methodical and logical answers to all these questions. They give you ample amount of practice on different concepts learnt. The part B of Xam Idea Class 12 Chemistry Book has several model papers and previous year’s question papers. You are advised to solve these also so that you get the exact idea of how questions are framed for exams.

Benefits of Xam Idea Class 12 Chemistry Chapter 3 – Electrochemistry

Some of the benefits of learning and revising from our Xam Idea Class 12 Chemistry Solutions Chapter 3 – Electrochemistry are listed below.

  • The solutions are written by experienced teachers in simple language.
  • They cover all the topics and subtopics of this chapter and give meticulous and detailed answers to all the questions asked in the chapter.
  • The solutions are prepared in a stepwise manner to clarify all your doubts instantly.
  • Our solutions are handy tools for comprehensive learning and problem-solving.
  • They help you in quick and effective revisions during class 12 board exams and other competitive exams so that you can achieve good marks.
  • They comprise smart problem-solving shortcuts and effective learning methodologies that help you improve your overall speed and efficiency.
  • They help you build a strong conceptual foundation
  • They make learning fun, interesting, engaging, interactive, efficient