Electrochemistry — Class 12 Chemistry NCERT Solutions (Free)
Free step-by-step NCERT solutions for Class 12 Chemistry chapter "Electrochemistry" — 8 important questions with detailed answers for CBSE board exam preparation.
✓ 100% Free
✓ No Login Needed
✓ NCERT / CBSE Aligned
✓ Download as PDF
TL;DR: Free step-by-step NCERT solutions for Class 12 Chemistry chapter "Electrochemistry" — 8 important questions with detailed answers for CBSE board exam…
Written & reviewed by the Syllab.in Academic Team (CBSE/NCERT subject experts) · Updated
🤖 Stuck on any question? Ask Syllab's free AI Tutor for a step-by-step explanation — instant, unlimited, no login.
Key Questions Covered:
- Define electrochemistry. What are electrodes and electrolytes?
- Write the Nernst equation and explain its significance.
- Calculate the standard cell potential for the reaction: Cu²⁺ + Zn → Cu + Zn²⁺…
- Explain the working of a galvanic cell. What happens at anode and cathode?
- Calculate moles of Cu deposited when 2 A of current is passed for 1.5 hours t…
- What is electrolysis? Explain the electrolysis of molten NaCl.
- + 2 more questions in the full chapter
Solutions Summary:
| Question | Status |
|---|---|
| Define electrochemistry. What are electrodes and electrol… | ✓ Solved |
| Write the Nernst equation and explain its significance. | ✓ Solved |
| Calculate the standard cell potential for the reaction: C… | ✓ Solved |
| Explain the working of a galvanic cell. What happens at a… | ✓ Solved |
| Calculate moles of Cu deposited when 2 A of current is pa… | ✓ Solved |
| What is electrolysis? Explain the electrolysis of molten … | ✓ Solved |
Showing 6 of 8 questions
Q1: Define electrochemistry. What are electrodes and electrolytes?
Electrochemistry is the study of chemical reactions that produce electrical current or the use of electrical current to drive non-spontaneous chemical reactions.
Electrode:
A conductor (usually metal or graphite) through which current enters or leaves an electrolytic cell or galvanic cell.
Types:
1. Anode: Electrode where oxidation occurs; positive in galvanic cell, negative in electrolytic cell
2. Cathode: Electrode where reduction occurs; negative in galvanic cell, positive in electrolytic ce...
Q2: Write the Nernst equation and explain its significance.
The Nernst equation relates cell potential to concentration of reactants and products at non-standard conditions.
Nernst Equation:
E_cell = E°_cell - (RT/nF) × ln(Q)
Alternative form (at 25°C):
E_cell = E°_cell - (0.0592/n) × log(Q)
where:
E_cell = cell potential at non-standard conditions
E°_cell = standard cell potential
R = universal gas constant (8.314 J/mol·K)
T = absolute temperature (K)
n = number of electrons transferred
F = Faraday constant (96485 C/mol)
Q = reaction quotient
Signif...
Q3: Calculate the standard cell potential for the reaction: Cu²⁺ + Zn → Cu + Zn²⁺. (Given: E°(Cu²⁺/Cu) = +0.34 V, E°(Zn²⁺/Zn) = -0.76 V)
Given:
Cu²⁺ + Zn → Cu + Zn²⁺
E°(Cu²⁺/Cu) = +0.34 V
E°(Zn²⁺/Zn) = -0.76 V
Step 1: Identify oxidation and reduction
Zn → Zn²⁺ + 2e⁻ (oxidation, occurs at anode)
Cu²⁺ + 2e⁻ → Cu (reduction, occurs at cathode)
Step 2: Calculate standard cell potential
E°_cell = E°(cathode) - E°(anode)
E°_cell = E°(Cu²⁺/Cu) - E°(Zn²⁺/Zn)
E°_cell = (+0.34) - (-0.76)
E°_cell = 0.34 + 0.76
E°_cell = +1.10 V
Interpretation:
E°_cell = +1.10 V (positive value)
The reaction is spontaneous under standard conditions.
This ...
Q4: Explain the working of a galvanic cell. What happens at anode and cathode?
A galvanic cell (voltaic cell) spontaneously converts chemical energy into electrical energy through redox reactions.
Working principle:
Redox reaction occurs spontaneously in two separated compartments (half-cells), driving electron flow through external circuit.
At Anode (negative terminal in galvanic cell):
1. Oxidation occurs: Loss of electrons
2. Anode material is oxidized
3. Electrons are released here and flow to cathode through external circuit
4. Anions from salt bridge move toward an...
Q5: Calculate moles of Cu deposited when 2 A of current is passed for 1.5 hours through CuSO₄ solution.
Given:
Current (I) = 2 A
Time (t) = 1.5 hours = 1.5 × 3600 = 5400 s
Reaction: Cu²⁺ + 2e⁻ → Cu
Step 1: Calculate total charge passed
Charge (Q) = I × t = 2 × 5400 = 10,800 C
Step 2: Determine electrons required per Cu atom
Cu²⁺ + 2e⁻ → Cu
For 1 Cu atom, 2 electrons are required
Step 3: Calculate moles of electrons
Moles of electrons = Q / F
where F = Faraday constant = 96,500 C/mol
Moles of electrons = 10,800 / 96,500 = 0.1119 mol
Step 4: Calculate moles of Cu deposited
From equation: 2 mol e...
Q6: What is electrolysis? Explain the electrolysis of molten NaCl.
Electrolysis is the process of using electrical current to drive non-spontaneous redox reactions in an electrolytic cell.
Electrolysis of molten NaCl:
Setup:
1. Molten NaCl contains Na⁺ and Cl⁻ ions
2. Inert electrodes (typically graphite or platinum) used
3. External source provides electric current
At Cathode (negative electrode):
Reduction occurs: Na⁺ + e⁻ → Na
Sodium metal deposits on cathode.
At Anode (positive electrode):
Oxidation occurs: 2Cl⁻ → Cl₂ + 2e⁻
Chlorine gas is produced at a...
Showing 6 of 8 questions. Visit the full page for complete solutions.
More Class 12 Chemistry NCERT Solutions
- Solutions — Class 12 Chemistry NCERT Solutions
- Chemical Kinetics — Class 12 Chemistry NCERT Solutions
- The D and F Block Elements — Class 12 Chemistry NCERT Solutions
- Coordination Compounds — Class 12 Chemistry NCERT Solutions
- Haloalkanes and Haloarenes — Class 12 Chemistry NCERT Solutions
- Alcohols Phenols and Ethers — Class 12 Chemistry NCERT Solutions
- Aldehydes Ketones and Carboxylic Acids — Class 12 Chemistry NCERT Solutions
- Amines — Class 12 Chemistry NCERT Solutions
- Biomolecules — Class 12 Chemistry NCERT Solutions