Asksia AI LOGO

Sia

青州's Question
Chemistry
Posted 6 months ago

The oxidation of 2.0×101 mL2.0 \times 10^{1} \mathrm{~mL} of a solution containing Fe2+\mathrm{Fe}^{2+} requires 29 mL29 \mathrm{~mL}. of 0.0190MK2Cr2O70.0190 \mathrm{M} \mathrm{K}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7} in acidic solution.
Part: 0/20 / 2
Part 1 of 2
Balance the following equation (in acidic solution). Do not include the states of each species.
Cr2O72+Fe2++H+Cr3++Fe3+
\mathrm{Cr}_{2} \mathrm{O}_{7}^{2-}+\mathrm{Fe}^{2+}+\mathrm{H}^{+} \rightarrow \mathrm{Cr}^{3+}+\mathrm{Fe}^{3+}
Sign in to unlock the answer
Answer from Sia
Posted 6 months ago
Solution
1
Identify the half-reactions: The given reaction involves the oxidation of Fe2+^{2+} to Fe3+^{3+} and the reduction of Cr2_2O72_7^{2-} to Cr3+^{3+}. The half-reactions are: Oxidation: Fe2+Fe3++e \text{Oxidation: } \mathrm{Fe}^{2+} \rightarrow \mathrm{Fe}^{3+} + e^- Reduction: Cr2O72+14H++6e2Cr3++7H2O \text{Reduction: } \mathrm{Cr}_2\mathrm{O}_7^{2-} + 14\mathrm{H}^+ + 6e^- \rightarrow 2\mathrm{Cr}^{3+} + 7\mathrm{H}_2\mathrm{O}
2
Balance the electrons: To balance the electrons lost in the oxidation half-reaction with those gained in the reduction half-reaction, multiply the oxidation half-reaction by 6: 6Fe2+6Fe3++6e 6\mathrm{Fe}^{2+} \rightarrow 6\mathrm{Fe}^{3+} + 6e^- Now, the electrons are balanced
3
Combine the half-reactions: Add the balanced half-reactions together: Cr2O72+14H++6Fe2+2Cr3++7H2O+6Fe3+ \mathrm{Cr}_2\mathrm{O}_7^{2-} + 14\mathrm{H}^+ + 6\mathrm{Fe}^{2+} \rightarrow 2\mathrm{Cr}^{3+} + 7\mathrm{H}_2\mathrm{O} + 6\mathrm{Fe}^{3+}
Answer
Cr2O72+14H++6Fe2+2Cr3++7H2O+6Fe3+\mathrm{Cr}_2\mathrm{O}_7^{2-} + 14\mathrm{H}^+ + 6\mathrm{Fe}^{2+} \rightarrow 2\mathrm{Cr}^{3+} + 7\mathrm{H}_2\mathrm{O} + 6\mathrm{Fe}^{3+}
Key Concept
Balancing redox reactions in acidic solution
Explanation
The key to balancing redox reactions in acidic solution is to separate the reaction into oxidation and reduction half-reactions, balance each half-reaction for mass and charge, and then combine them, ensuring that the electrons lost and gained are equal.

Not the question you are looking for? Ask here!

Enter question by text

Enter question by image

Unlock Smarter Learning with AskSia Super!

Join Super, our all-in-one AI solution that can greatly improve your learning efficiency.

30% higher accuracy than GPT-4o
Entire learning journey support
The most student-friendly features
Study Other Question