Batteries Using Chemistry to Generate Electricity

It has been suggested that one cause of the decline of the Roman Empire was widespread chronic poisoning. The suspected source was a metal present in the vessels commonly used to store and serve acidic substances such as wine. Which metal would you expect to pose such a danger  

The fuel cell that we discussed in the opening section of this chapter is a type of electrochemical cell. 

The salt bridge completes the circuit—it allows the flow of ions between the two half-cells. 

When Zn metal is placed into a Cu solution, Zn is oxidized and Cu is reduced—electrons are transferred directly from the Zn to the Cu . Suppose we separate the reactants and force the electrons to travel through a wire to get from the Zn to the Cu . The flowing electrons constitute an electrical current and can be used to do electrical work. This process is normally carried out in an electrochemical cell, a device that creates electrical current from a spontaneous redox reaction (or that uses electrical current to drive a nonspontaneous redox reaction). Electrochemical cells that create electrical current from spontaneous reactions are called voltaic cells or galvanic cells. A battery is a voltaic cell that (usually) has been designed for portability. 

In a voltaic cell, the metal strip where oxidation occurs is called the anode and is labeled with a negative (-) sign. The metal strip where reduction occms is called the cathode and is labeled with a (-I-) sign. Electrons flow from the anode to the cathode (away from negative and toward positive). 

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The End of the Internal Combustion Engine 577 16.4 Balancing Redox Equations 584 16.6 Batteries Using Chemistry to Generate Electricity 593... 

Fuel cells have been used to provide electrical power for spacecraft since the 1960s. In recent years, fuel cell technology has begun to mature, and batteries made up of fuel cells will soon be or are now available for small-.scale power generation and electric automobiles. Use your Web browser to connect to http // chemistry.brookscole.com/skoogfac/. From the Chapter Resources menu, choose Web Works. Locate the Chapter 18 section and click on the link to the Scientific American Web site article on fuel cells. Describe a proton-exchange membrane from the information and links given. 

HAVE YOU EVER WONDERED why the stars shine Or why leaves change color in the fall or how a battery generates electricity Have you ever wondered why keeping foods cold slows their spoilage and how our bodies use food to maintain life Chemistry answers these questions as well as countless others. 

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