7 public questions tagged with this topic.
In CoCl₂, Cl = -1 (2 chlorines = -2). For neutrality, Co = +2. This follows from latest NCERT 2026-27 principle explaining the concept clearly for NEET students in simple steps as per rationalized syllabus.
Ref: NCERT Chemistry Textbook - Latest Edition for Academic Session 2026-27 (Rationalized Textbook for Class XI and XII)Topic: Mole concept, atomic structure, chemical formulas like H₂O, CO₂, CH₃CH₂NH₂ and periodic trends.
Given: What is the oxidation state of cobalt in [Co(en)2Cl₂]Cl ? Formula: The complex charge is +1 (balanced by 1 Cl⁻), so Co’s oxidation state is x - 2 = +1, x = +3 .. Substitution & Calculation: In [Co(en)2Cl₂]+, 2 en are neutral, 2 Cl^- contribute -2. Final Result: The computed value matches expected outcome and confirms correct choice as per latest NCERT 2026-27.
Ref: NCERT Chemistry Textbook - Latest Edition for Academic Session 2026-27 (Rationalized Textbook for Class XI and XII), Chapter: Electrochemistry (Latest NCERT 2026-27), Topic: Faraday's laws, charge required to reduce Al³⁺, 3F = 3 × 96500 C
[Co(NH₃)4Cl₂]+ has 2 isomers (cis, trans). [Co(NH₃)2(H₂O)2Cl₂]+ (Ma₂b2c2) has 3 (all cis, cis-trans-cis, all trans).
Ref: NCERT Class 12 Chemistry > Chapter 5: Coordination Compounds > Topic: Isomerism - Geometrical Isomerism in Coordination Compounds
In [Co(en)2Cl₂]NO₃, [Co(en)2Cl₂]+ balances NO₃−. Each en is neutral, each Cl− is −1. Thus, x + 0 + 2(−1) = +1, so x = +3.
Ref: NCERT Class 12 Chemistry > Chapter 5: Coordination Compounds > Topic: Colour and Magnetic Properties and Stability and Importance
E°cell = 0.00 - (-0.28) = 0.28 V . Ecell = 0.28 - (0.059/2) log (0.02/0.01²) = 0.28 - 0.07375 = 0.20625 V .
Ref: NCERT Class 12 Chemistry > Chapter 2: Electrochemistry > Topic: Nernst Equation and Gibbs Energy and Equilibrium Constant
E°cell = 1.07 - (-0.28) = 1.35 V . Ecell = 1.35 - (0.059/2) log ([Co²⁺][Br⁻]²/1) = 1.35 - 0.0295 log (0.01 × 0.0025) = 1.35 + 0.073 = 1.423 V .
Ref: NCERT Class 12 Chemistry > Chapter 2: Electrochemistry > Topic: Nernst Equation and Gibbs Energy and Equilibrium Constant
E°cell = E°cathode - E°anode = 0.80 - (-0.28) = 1.08 V .
Ref: NCERT Class 12 Chemistry > Chapter 2: Electrochemistry > Topic: Electrochemical Cells - Galvanic Cells and Electrode Potential
