【People's Education Press】High School Chemistry: Selective Compulsory Course 1: The Power Source of Modern Civilization: Energy Conversion between Chemical and Electrical Energy

Imagine a quiet surface on Mars,Zhurong roverhow does the probe survive and keep operating through freezing nights? The answer lies in the microscopic jumps of electrons—electrochemistry.

Electrochemistry is the science that studies the laws governing the mutual conversion of chemical and electrical energy. It serves as the technological core by enabling controlled release and storage of energy through the directional movement of electrons in redox reactions. In modern energy systems, this transformation manifests in two fundamental forms:

Core Principles and Logic

Spontaneous vs. Controlled: A galvanic cell converts chemical bond energy directly into electron kinetic energy (electricity) via spontaneous redox reactions, achieving instantaneous energy release.
Driving and Storage: An electrolytic cell uses external current to force non-spontaneous reactions, re-encapsulating electron kinetic energy back into chemical bonds to complete energy storage.
Closed-loop Ecosystem: This exchange between 'chemical bond energy ↔ electron kinetic energy' not only powers our smartphones and electric vehicles but also forms the foundation for electro-metallurgy, metal corrosion prevention, and future hydrogen-based economies.

QUESTION 1

[Short Answer] High-purity PbO can be produced using lead-containing waste from spent lead-acid batteries and $H_2SO_4$. The following two reactions are involved in this process:
① $2Fe^{2+} + PbO_2 + 4H^+ + SO_4^{2-} = 2Fe^{3+} + PbSO_4 + 2H_2O$
② $2Fe^{3+} + Pb + SO_4^{2-} = 2Fe^{2+} + PbSO_4$
(1) Write the chemical equation for the reaction between Pb and $PbO_2$ to form $PbSO_4$.
(2) What is the role of $Fe^{2+}$ in this process?
(3) Design an experimental procedure to demonstrate the role of $Fe^{2+}$.

QUESTION 2

[Short Answer] What is chemical corrosion of metals? What is electrochemical corrosion? Provide examples illustrating the hazards of metal corrosion.

QUESTION 3

[Multiple Choice] In the setup shown below, all beakers contain seawater. Which of the following can protect iron from corrosion? ( )
A. Iron directly contacting carbon
B. Iron connected to carbon via wire
C. Iron connected to tin
D. Iron connected to zinc

QUESTION 4

[Multiple Choice] The overall reaction of an alkaline zinc-manganese battery is: $Zn + 2MnO_2 + 2H_2O = 2MnO(OH) + Zn(OH)2$. Which of the following statements about this battery is correct? ( ).

Zn is the positive electrode, undergoing reduction

MnO₂ is the positive electrode, undergoing reduction

During operation, electrons flow from MnO₂ through the external circuit to Zn

This battery is a secondary battery and can be recharged multiple times