• The equation of the redox half-reactions is given as follows:
Cr2O2^-7(aq) + Fe^2+ (aq) → Cr^3+(aq) + Fe^3+(aq)
• adding this to n acidic solution will produce the following: see equations in the box below:
[tex]\begin{gathered} 1.Balance\text{ the Cr atom } \\ \rightarrow Cr_2O^{2-}_7+6e^-\rightarrow2cr^{3+} \\ 2.\text{ Balance the }Fe\text{ electrons by multiplying with 6 } \\ \rightarrow6Fe^{2+}\rightarrow6Fe^{3+\text{ }} \\ 3.\text{ Balance the oxygen atoms },\text{ 7Oxygen on the left side, so 7Oxygen on the right side } \\ \rightarrow Cr_2O^{2-\text{ }}_{7^{}}+6Fe^{2+}+\text{ }\rightarrow6Fe^{3+\text{ }}+2Cr^{3+}+\text{ }7H2O \\ 4\text{. balance the H atoms } \\ \rightarrow Cr_2O^{2-\text{ }}_7+6Fe^{2+}+\text{ }14H^+\rightarrow6Fe^{3+}+2cr^{3+}+7H_2O \end{gathered}[/tex]