What is the oxidation number of carbon in CH₄?
Let C = x. H = +1. Equation: x + 4(+1) = 0, x + 4 = 0, x = -4.
Ref: NCERT Class 11 Chemistry > Chapter 7: Redox Reactions > Topic: Electrode Potential and Electrochemical Series and Galvanic Cells
Electrode Potential and Electrochemical Series and Galvanic Cells
This category focuses on electrode potential, the electrochemical series, and the operation of galvanic cells. Learn how these concepts relate to electrochemistry and solve problems involving cell potentials and reactions.
Filter questions
Which compound contains an element with an oxidation number lower than in CO₂?
C in CO₂: +4. In CH₂O: x + 2(+1) + (-2) = 0, x = 0, which is lower.
Ref: NCERT Class 11 Chemistry > Chapter 7: Redox Reactions > Topic: Electrode Potential and Electrochemical Series and Galvanic Cells
Which of the following reactions involves a redox process with a non-metal?
In S₈ + 8O₂ → 8SO₂, S (0) is oxidized to +4, and O (0) is reduced to -2.
Ref: NCERT Class 11 Chemistry > Chapter 7: Redox Reactions > Topic: Electrode Potential and Electrochemical Series and Galvanic Cells
In the reaction PbS + 4H₂O₂ → PbSO₄ + 4H₂O, which element is reduced?
O (-1 in H₂O₂) becomes -2 in H₂O, gaining electrons.
Ref: NCERT Class 11 Chemistry > Chapter 7: Redox Reactions > Topic: Electrode Potential and Electrochemical Series and Galvanic Cells
In the reaction H₂S + Cl₂ → 2HCl + S, which element is oxidized?
Oxidation involves electron loss. S (-2 in H₂S) becomes 0 in S, losing electrons.
Ref: NCERT Class 11 Chemistry > Chapter 7: Redox Reactions > Topic: Electrode Potential and Electrochemical Series and Galvanic Cells
What is the oxidation number of sulfur in H₂S?
Let S = x. H = +1. Equation: 2(+1) + x = 0, 2 + x = 0, x = -2.
Ref: NCERT Class 11 Chemistry > Chapter 7: Redox Reactions > Topic: Electrode Potential and Electrochemical Series and Galvanic Cells
In 2MnO₄− + 5C₂O₄²− + 16H+ → 2Mn²⁺ + 10CO₂ + 8H₂O, which species contains the element oxidized?
C (+3 in C₂O₄²−) to +4 in CO₂ is oxidized; Mn (+7 to +2) is reduced.
Ref: NCERT Class 11 Chemistry > Chapter 7: Redox Reactions > Topic: Electrode Potential and Electrochemical Series and Galvanic Cells
In the reaction 2KI + Br₂ → 2KBr + I₂, which species is the reducing agent?
KI (I: -1 to 0 in I₂) loses electrons, reducing Br₂ (0 to -1).
Ref: NCERT Class 11 Chemistry > Chapter 7: Redox Reactions > Topic: Electrode Potential and Electrochemical Series and Galvanic Cells
What is the oxidation number of osmium in OsO₄?
Let Os = x. O = -2. Equation: x + 4(-2) = 0, x - 8 = 0, x = +8.
Ref: NCERT Class 11 Chemistry > Chapter 7: Redox Reactions > Topic: Electrode Potential and Electrochemical Series and Galvanic Cells
Which reaction demonstrates the loss of electrons by a metal?
In 2Al + 3Cl₂ → 2AlCl₃, Al (0) loses electrons to become Al₃+ (+3).
Ref: NCERT Class 11 Chemistry > Chapter 7: Redox Reactions > Topic: Electrode Potential and Electrochemical Series and Galvanic Cells
In the reaction 3Br₂ + 6NaOH → 5NaBr + NaBrO₃ + 3H₂O, which species is the oxidizing agent?
Br₂ (0) is reduced to -1 in NaBr and oxidized to +5 in NaBrO₃, acting as its own oxidizing agent.
Ref: NCERT Class 11 Chemistry > Chapter 7: Redox Reactions > Topic: Electrode Potential and Electrochemical Series and Galvanic Cells
Which reaction involves the addition of oxygen to a metal?
In 4Na + O₂ → 2Na₂O, Na gains oxygen to form Na₂O, an oxidation process.
Ref: NCERT Class 11 Chemistry > Chapter 7: Redox Reactions > Topic: Electrode Potential and Electrochemical Series and Galvanic Cells
