Dinitrogen tetroxide chemical reactions

Figure 7.7 shows how the law of chemical equilibrium applies to one chemical system. Chemists have studied this system extensively. It involves the reversible reaction between two gases dinitrogen tetroxide, which is colourless, and nitrogen dioxide, which is dark brown. 

In previous chapters, we ve generally assumed that chemical reactions result in complete conversion of reactants to products. Many reactions, however, do not go to completion. Take, for example, the decomposition of the colorless gas dinitrogen tetroxide (N2O4) to the dark brown gas nitrogen dioxide (NO2). 

SAFETY PROFILE Moderately toxic by inhalation. A very dangerous fire and explosion hazard when exposed to heat, flame, or oxidizers. Powerful explosive reaction with dinitrogen tetroxide. To fight fire, use water, foam, CO2, dry chemical. When heated it emits acrid smoke and irritating fumes. See also TIN COMPOUNDS and ORGANOMETALS. 

Sometimes a chemical reaction begins, continues for a while, and then appears to stop before any one of the reactants is used up the reaction is said to have reached equilibrium. The reaction between nitrogen dioxide, NOo, and dinitrogen tetroxide, NgO, provides an interesting example. The gas that is obtained by heating concentrated... 

In some cases it has been found possible to determine the rates of the opposing reactions, and to show experimentally that the ratio of the two rate constants is indeed equal to the equilibrium constant. This has not been done for the nitrogen dioxide-dinitrogen tetroxide equilibrium, however, because the individual chemical reactions take place so rapidly that expetimenters have not been able to determine their rates. It has, indeed, been found by experiment that if the pressure... 

The great rate at which a chemical reaction may occur has been mentioned above in the discussion of the NOg-NgO equilibrium. It was pointed out that the decomposition of dinitrogen tetroxide or reformation of these molecules from nitrogen dioxide molecules occurs within... 

The study of physical equilibrium yields useful information, such as the equilibrium vapor pressure (see Section 11.8). However, chemists are particularly interested in chemical equilibrium processes, such as the reversible reaction involving nitrogen dioxide (NO2) and dinitrogen tetroxide (N2O4) (Figure 14.1). The progress of the reaction... 

So far in this textbook we have usually assumed that reactions proceed to completion—that is, until one of the reactants "runs out." Indeed, many reactions do proceed essentially to completion. For such reactions we can assume that the reactants are converted to products until the limiting reactant is completely consumed. On the other hand, there are many chemical reactions that "stop" far short of completion when they are allowed to take place in a closed container. An example is the reaction of nitrogen dioxide to form dinitrogen tetroxide. 

Another question that arises is why chemical reactions carried out in a closed vessel appear to stop at a certain point. For example, when the reaction of reddish-brown nitrogen dioxide to form colorless dinitrogen tetroxide. 

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