Redox Reactions — Class 11 Chemistry NCERT Solutions (Free)
Free step-by-step NCERT solutions for Class 11 Chemistry chapter "Redox Reactions" — 8 important questions with detailed answers for CBSE board exam preparation.
TL;DR: Free step-by-step NCERT solutions for Class 11 Chemistry chapter "Redox Reactions" — 8 important questions with detailed answers for CBSE board exam p…
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Key Questions Covered:
- Define oxidation and reduction. Are they always simultaneous?
- Determine oxidation numbers of all atoms in K2Cr2O7 and KMnO4
- Balance the redox equation: MnO4- + Fe2+ -> Mn2+ + Fe3+ in acidic medium
- + 5 more questions in the full chapter
Solutions Summary:
| Question | Status |
|---|---|
| Define oxidation and reduction. Are they always simultane… | ✓ Solved |
| Determine oxidation numbers of all atoms in K2Cr2O7 and K… | ✓ Solved |
| Balance the redox equation: MnO4- + Fe2+ -> Mn2+ + Fe3+ i… | ✓ Solved |
Showing 3 of 8 questions
Q1: Define oxidation and reduction. Are they always simultaneous?
Oxidation: Loss of electrons or increase in oxidation number.
Reduction: Gain of electrons or decrease in oxidation number.
Redox reaction: A reaction in which both oxidation and reduction occur simultaneously.
They are ALWAYS simultaneous because:
- Electrons lost by one species must be gained by...
Q2: Determine oxidation numbers of all atoms in K2Cr2O7 and KMnO4
Oxidation number rules:
- Alkali metals (Group 1) = +1
- Alkaline earth metals (Group 2) = +2
- Oxygen in compounds = -2 (except peroxides)
- Sum = charge on compound (for neutral: sum = 0)
In K2Cr2O7:
K: +1 (Group 1)
Cr: ?
O: -2
2(+1) + 2(Cr) + 7(-2) = 0
2 + 2Cr - 14 = 0
2Cr = 12
Cr = +6
In KMnO...
Q3: Balance the redox equation: MnO4- + Fe2+ -> Mn2+ + Fe3+ in acidic medium
Step 1: Identify oxidation states
Mn in MnO4-: +7 (reduction, gains 5e-)
Fe2+: +2 (oxidation, loses 1e-)
Step 2: Write half-reactions
Reduction: MnO4- -> Mn2+
Oxidation: Fe2+ -> Fe3+
Step 3: Balance half-reactions (acidic medium)
Reduction: MnO4- + 8H+ + 5e- -> Mn2+ + 4H2O
Oxidation: Fe2+...
Showing 3 of 8 questions. Visit the full page for complete solutions.