Question

This reaction takes place in acid. Balance Hydrogen using H⁺ for these half-reactions:

Cr₂O₇⁻² + 6e⁻ = 2Cr⁺³ + 7H₂O
C₂O₄⁻² = 2CO₂ + 2e⁻

Answer 1

To balance hydrogen in an acidic solution, add H+ ions. For the provided half-reaction, 14 H+ ions balance the hydrogen, resulting in a fully balanced reaction with correct stoichiometry and electron balance.

Step-by-step explanation:

The question involves balancing hydrogen using H+ for half-reactions in an acidic solution. In the half-reaction Cr2O72- + 6e- = 2Cr3+ + 7H2O, you must add 14 H+ ions to the reactants to balance the hydrogen atoms. Now, the equation becomes 14 H+ (aq) + Cr2O72- (aq) + 6e- = 2Cr3+ (aq) + 7H2O (l).

The second half-reaction is C2O42- = 2CO2 + 2e-, which is already balanced and does not require additional hydrogen or H+ ions to balance it in an acidic medium.

Checking the balance, we see that the chromium and oxygen are now balanced, and by adding the electrons, we also balance the charges. These examples illustrate the method of balancing redox reactions in acidic solutions.