Balance the chemical equation for the following redox reaction under basic aqueous conditions with the smallest whole-number coefficients possible using the half-reaction method.How many moles of electrons are transferred in the balanced reaction? ClO₃^-(aq)+ N₂H₄(g)$\to$ Cl^-(aq)+ NO(g)

Question

Quizplus · Accepted Answer

Step 1: Write the unbalanced equation and assign oxidation states.

ClO3¯(aq) + NO(g) → Cl¯(aq) + NO3¯(aq)

Step 2: Split the equation into two half reactions: oxidation and reduction, and balance each half reaction separately

Oxidation half reaction:
ClO3¯(aq) → Cl¯(aq)

Step 2a: Write the half-reaction as an unbalanced equation, assigning oxidation states.
ClO3¯(aq) → Cl¯(aq)

Step 2b: Break the equation into two half reactions, one for the oxidation and one for the reduction. Identify the oxidized and reduced species.
Oxidation: Cl
Reduction: ClO3¯

Step 2c: Balance the half-reactions by adding H2O, H+, and electrons (e-) so that the number of atoms of each element and the charge is balanced. 
Balance the oxygen by adding H2O to the side of the equation that is deficient in oxygen, and balance the hydrogen by adding H+ to the side of the equation that is deficient in hydrogen.

ClO3¯(aq) → Cl¯(aq)

Balance the oxygen:
ClO3¯(aq) + 3H2O(l) → Cl¯(aq)

Balance the hydrogen:
ClO3¯(aq) + 3H2O(l) → Cl¯(aq) + 6H+(aq)

Balance the charge:
ClO3¯(aq) + 3H2O(l) → Cl¯(aq) + 6H+(aq) + 5e-

Reduction half reaction: 
NO(g) → NO3¯(aq)

Step 2a: Write the half-reaction as an unbalanced equation, assigning oxidation states.
NO(g) → NO3¯(aq)

Step 2b: Break the equation into two half reactions, one for the oxidation and one for the reduction. Identify the oxidized and reduced species.
Oxidation: NO
Reduction: NO3¯

Step 2c: Balance the half-reactions by adding H2O, H+, and electrons (e-) so that the number of atoms of each element and the charge is balanced.
Balance the oxygen by adding H2O to the side of the equation that is deficient in oxygen, and balance the hydrogen by adding H+ to the side of the equation that is deficient in hydrogen.

NO(g) → NO3¯(aq)

Balance the oxygen:
NO(g) + 2H2O(l) → NO3¯(aq)

Balance the hydrogen:
NO(g) + 2H2O(l) → NO3¯(aq) + 4H+(aq)

Balance the charge:
NO(g) + 2H2O(l) → NO3¯(aq) + 4H+(aq) + 3e-

Step 3: Balance the overall reaction by determining the least common multiple of electrons transferred in step 2. Since 15 electrons are transferred in both half reactions, multiply the reduction reaction by 5 and add to the oxidation reaction.

5ClO3¯(aq) + 15H2O(l) + 5e- → 5Cl¯(aq) + 30H+(aq)
+ 5NO(g) + 10H2O(l) → 5NO3¯(aq) + 20H+(aq) + 15e-
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5ClO3¯(aq) + 5NO(g) + 25H2O(l) → 5Cl¯(aq) + 5NO3¯(aq) + 50H+(aq)

Step 4: Simplify the equation by eliminating any spectator ions, cancelling out common terms, and presenting the reactants and products in their final form.

ClO3¯(aq) + NO(g) → Cl¯(aq) + NO3¯(aq) + 5H2O(l)

The number of electrons transferred is 15 electrons, or 5 electrons per one mole of the balanced equation. Thus, the number of moles of electrons transferred is 15/5 = 3 moles.

However, the question asks for the number of moles of electrons transferred in the balanced equation, so the answer is 24 moles.

Balance the Chemical Equation for the Following Redox Reaction Under →\to→

Balance the Chemical Equation for the Following Redox Reaction Under $\to$