Table of contents | |
Introduction | |
Batteries | |
Fuel Cells | |
Corrosion | |
Catalysis | |
Enzyme Catalysis |
Electrolysis is conducted in an electrolytic cell, where an external voltage source induces a chemical reaction. A basic electrolytic cell includes two copper strips immersed in an aqueous copper sulfate solution. When DC voltage is applied to the electrodes, copper metal is deposited on the cathode, and copper dissolves at the anode.
Applications of Electrolysis:
In primary batteries, the reaction occurs only once, and the battery eventually becomes dead.
Secondary batteries can be recharged by passing current through them in the opposite direction.
Fuel cells directly convert the energy from fuel combustion (e.g., hydrogen, carbon monoxide, methane) into electrical energy. A hydrogen-oxygen fuel cell, used in the Apollo Space Program, bubbles H2 and O2 through porous carbon electrodes into a concentrated aqueous sodium hydroxide solution, with palladium or platinum catalysts enhancing electrode efficiency. Hydrogen-oxygen fuel cells are non-polluting, producing only water as a byproduct, and operate with an efficiency of 70-75%, providing continuous energy.
Microbial Fuel Cells (MFCs)
MFCs are bioelectrochemical devices used in water treatment to harvest energy through anaerobic digestion, collecting bioenergy from wastewater.
Many metals, such as iron, are easily corroded by air and water. Rust, a brown flaky substance, forms on iron exposed to moist air, primarily consisting of hydrated iron (III) oxide (Fe2O3·xH2O). Other examples of corrosion include the tarnishing of silver and the formation of green coatings on copper or bronze. Corrosion involves the oxidation of a metal by losing electrons to oxygen. Rusting of iron can be prevented by painting, oiling, greasing, galvanizing (zinc coating), or chrome plating.
A catalyst alters the rate of a reaction without being consumed in the process, remaining unchanged in mass and composition. Catalysis refers to the phenomena where a catalyst affects the reaction rate. A solid catalyst is typically more effective when finely divided. Catalysts do not initiate reactions or change the equilibrium state of reversible reactions; they merely speed up the process by lowering the activation energy.
Applications in Industrial Processes:
Enzyme catalysis involves enzymes increasing the rate of reactions. Enzymes, which are proteins, are highly specific and sensitive to temperature, with an optimum range between 25-37°C. The rate of enzymatic reactions is significantly affected by pH changes.
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1. What is the difference between batteries and fuel cells? |
2. How does corrosion impact the efficiency of batteries and fuel cells? |
3. What role does catalysis play in the functioning of batteries and fuel cells? |
4. How does enzyme catalysis contribute to the development of more efficient batteries and fuel cells? |
5. How can electrolysis be used in the production of batteries and fuel cells? |
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