Standard reduction potential 1296 Compound

Table 4. Standard Reduction Potentials for Selected Manganese Compounds...

Preparation and chemistry of chromium compounds can be found ia several standard reference books and advanced texts (7,11,12,14). Standard reduction potentials for select chromium species are given ia Table 2 whereas Table 3 is a summary of hydrolysis, complex formation, or other equilibrium constants for oxidation states II, III, and VI. 

The standard reduction potential of Cr " (Table 2) shows that this ion is a strong reducing agent, and Cr(II) compounds have been used as reagents in analytical chemistry procedures (26). The reduction potential also explains why Cr(II) compounds are unstable in aqueous solutions. In the presence of air, the oxidation to Cr(III) occurs by reaction with oxygen. However, Cr(II) also reacts with water in deoxygenated solutions, depending on acidity and the anion present, to produce H2 and Cr(III) (27,28). 

Copper compounds, which represent only a small percentage of ah copper production, play key roles ia both iadustry and the biosphere. Copper [7440-50.8] mol wt = 63.546, [Ar]3/°4.t is a member of the first transition series and much of its chemistry is associated with the copper(II) ion [15158-11-9] [Ar]3i5. Copper forms compounds of commercial iaterest ia the +1 and +2 oxidation states. The standard reduction potentials, for the reasonably attainable valence states of copper are... 

TII3 is an intriguing compound which is isomorphous with NH4I3 and Csly (p. 836) it therefore contains the linear I3 ion and is a compound of Tl rather than Tl . It is obtained as black crystals by evaporating an equimolar solution of Til and I2 in concentrated aqueous HI. The formulation Tl (l3 ) rather than Tl (I )y is consistent with the standard reduction potentials °(T1"VT1 )1.26 V and °(il2/I )-(-0.54 V,... 

The oxoacids of P are dearly very different structurally from those of N (p. 459) and this difference is accentuated when the standard reduction potentials (p. 434) and oxidation-stale diagrams (p. 437) for the two sets of compounds are compared. Some reduction potentials ( /V) in acid solution are in Table 12.8 (p. 513) and these are shown schematically below, together with the corresponding data for alkaline solutions. 

If the free element is less active than the corresponding element in the compound, no reaction will take place. A short list of metals in order of their reactivities and an even shorter list of nonmetals are presented in Table 7-1. The metals in the list range from very active to very stable the nonmetals listed range from very active to fairly active. A more comprehensive list, a table of standard reduction potentials, is presented in general chemistry textbooks. 

Transition metals tend to have higher melting points than representative metals. Because they are metals, transition elements have relatively low ionization energies. Ions of transition metals often are colored in aqueous solution. Because they are metals and thus readily form cations, they have negative standard reduction potentials. Their compounds often have unpaired electrons because of the diversity of -electron configurations, and thus, they often are paramagnetic. Consequently, the correct answers are (c) and (e). 

Standard Reduction Potentials (in Nonaqueous Solvents) and Adjusted First Orbital-Mediated Tunneling (OMT) Band Position (in t)) in a Variety of Compounds... 

Reduction potential is a measure of how thermodynamically favourable it is for a compound to gain electrons. A high positive value for a reduction potential indicates that a compound is readily reduced and consequently is a strong oxidising agent, i.e. it removes electrons from substances with lower reduction potentials. The oxidised and reduced form of a substance are known as a redox pair. Table 3.2 lists the standard reduction potentials for some typical redox pairs. 

I mm your understanding of the inert-pair clfeci anil the redox properties ol TI and I >. consider the apparent oxidation stale of 11 ui the compound I II and indicate what the realistic value is. flic standard reduction potential for the Tlm Tl1 couple is >. 25 V. 

The nature of ions in solution is described in some detail and enthalpies and entropies of hydration of many ions are defined and recalculated from the best data available. These values are used to provide an understanding of the periodicities of standard reduction potentials. Standard reduction potential data for all of the elements, group-bygroup, covering the s-and p-, d- and/- blocks of the Periodic Table is also included. Major sections are devoted to the acid/base behaviour and the solubilities of inorganic compounds in water. 

Redox pairs Oxidation (loss of electrons) of one compound is always accompanied by reduction (gain of electrons) of a second substance. For example, Figure 6.11 shows the oxidation of NADH to NAD+ accompanied by the reduction of FAD to FADH2. Such oxidation-reduction reactions can be written as the sum of two halfreactions an isolated oxidation reaction and a separate reduction reaction (see Figure 6.11). NAD+ and NADH form a redox pair, as do FAD and FADH2. Redox pairs differ in their tendency to lose electrons. This tendency is a characteristic of a particular redox pair, and can be quantitatively specified by a constant, E (the standard reduction potential), with units in volts. 

Table 3.1 Biological Standard Reduction Potentials (E ) for a Series of Antioxidant Compounds and Flavonoids and Biological Standard Free Energy Variation (AG" ) for the Reactions between These Compounds and Oxygen Free Radicals... 

Whether one metal will replace another metal from a compound is determined by the reduction potential of the metal, found on a table of standard reduction potentials (like the one available to you on the AP test). If the metallic element is higher on the chart than the cation, it will replace it. If it is not higher on the chart, no reaction will occur. 

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