Lithium standard reduction potential

Why is lithium metal becoming a popular electrode in modern batteries Use the standard reduction potentials table to help you answer this question. 

It is necessary to know the thermodynamic reduction potentials of the active metals in chloroaluminate melts. Scordilis-Kelley et al. [451,467] have studied standard reduction potentials in ambient temperature chloroaluminate melts for lithium and sodium, and they have calculated those of K, Rb, Cs. The values are, respectively, -2.066 V, -2.097 V, -2.71 V, -2.77 V and -2.87 V [versus A1(III)/A1 in a 1.5/1.0 A1C13/MEIC reference melt]. 

Why are the standard reduction potentials of lithium and beryllium out of line with respect to group trends ... 

The solution is to develop lightweight batteries that store a large amount of energy for their size. Engineers have focused their attention on the element lithium for two reasons lithium is the lightest known metal and has the lowest standard reduction potential of the metallic elements, —3.04 V, as shown in Table 20.1. A battery that oxidizes lithium at the anode can generate almost 2.3 V more than a similar battery in which zinc is oxidized. 

Compare the zinc and lithium oxidation half-reactions and their standard reduction potentials. 

Lithium has the most negative standard reduction potential (refer to Chapter 3 if you need a refresher on reduction reactions). 

The advantage of the battery is that lithium has the most negative standard reduction potential valne (see Table 13.1). Furthermore, lithium is the lightest metal, so that only 6.941 g of Li (its molar mass) is needed to produce 1 mole of electrons. A lithium-ion battery can be recharged literally hundreds of times without deterioration. These desirable characteristics make it suitable for use in cellular telephones, digital cameras, and laptop computers. 

The standard reduction potential of lithium is more negative than that of the solvated-electron system (at least in highly purified ammonia, amines and ethers). This results in the formation of the well known blue solutions of solvated electrons In rechargeable batteries under prolonged... 

With the preceding as a brief review of redox reactions, we can now turn to a discussion of the standard reduction potentials of the alkali metals, which are listed in Table 12.1. Specifically, we want to know what information they can provide and how such information can be put to use to understand better the characteristics of not only the alkali metals but also other groups of the periodic table. Take lithium as an example. The half-equation for the reduction of aqueous lithium ions to lithium metal is shown in Equation (12.9) ... 

Now we would like to compare the tendencies of the aqueous lithium cation and the other aqueous alkali metal cations to be reduced. To do this systematically, the reduction potentials must be measured under certain standard-state conditions. We need not concern ourselves with the details of standard states it is enough to note that as a first approximation the standard state for an aqueous solution specifies that all solutes are at a concentration of 1 molar (M) and all gases are at 1 atm of pressure. In addition, these conditions most always specify a temperature of 25°C or 298 K. Under these conditions we can refer to the standard reduction potential as the measure of the tendency of a substance to be reduced under standard conditions. The symbol for this is E°, where the degree sign specifies the standard conditions. 

Based on an analysis of standard reduction potentials, should it be more or less difficult to electrolyze lithium chloride to lithium metal or sodium chloride to sodium metal Provide a brief rationale for your answer. 

Explain in your own words why (a) the standard reduction potentials of potassium, rubidium, and cesium are so similar and />) why the standard reduction potential of lithium is so different from the above three. 

We will reconsider this process briefly because it illustrates several important concepts. Based on the ionization energies, we might expect lithium to be the weakest of the alkali metals as a reducing agent in water. However, the standard reduction potentials indicate that it is the strongest. This reversal results mainly from the very large energy of hydration... 

Because of lithium s low density and high standard potential difference (good oxidation reduction characteristics), cells using lithium at the anode have a very high energy density relative to lead, nickel and even zinc. Its high cost limits use to the more sophisticated and expensive electronic equipment. 

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