Redox Reactions for NEET UG
Redox reactions move electrons from one substance to another. They power batteries, rust iron, bleach clothes and keep you alive through respiration.
ChemistryClass 1170 MCQs2 lessons13 flashcards2 memory tricks
What you'll learn
- Oxidation numbers
Assign oxidation numbers and identify what is oxidised and reduced. - Balancing redox equations
Balance redox equations by the ion-electron (half-reaction) method.
Memory tricks
Oxidation Is Loss of electrons, Reduction Is Gain of electrons.
Oxygen's oxidation number is −2 in most compounds, −1 in peroxides (H₂O₂, Na₂O₂), −½ in superoxides (KO₂) and +2 in OF₂.
Try 3 NEET-style questions
Q1. The oxidation numbers of chlorine in HOCl, HClO₂, HClO₃ and HClO₄ are respectively
- −1, +1, +3, +5
- +1, +2, +3, +4
- +1, +3, +5, +7
- +7, +5, +3, +1
Show answer
Answer: (3) +1, +3, +5, +7
H = +1 and O = −2. HOCl: Cl = +1; HClO₂: +3; HClO₃: +5; HClO₄: +7.
Q2. The oxidation number of carbon in CH₃Cl is
- −4
- −2
- 0
- +2
Show answer
Answer: (2) −2
x + 3(+1) + (−1) = 0, so x = −2.
Q3. In the electrochemical series, a metal with a more negative standard reduction potential is
- a stronger oxidising agent
- less reactive
- unable to lose electrons
- a stronger reducing agent
Show answer
Answer: (4) a stronger reducing agent
A more negative E° means the metal loses electrons more readily, so it is a stronger reducing agent. Lithium (E° ≈ −3.05 V) is among the strongest reducing agents.
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