Nitrogen Dioxide, NO2 and

Let s apply the preceding two paragraphs to an example problem. The first-order decomposition of gaseous dinitrogen pentoxide, N205, to nitrogen dioxide, NO2, and oxygen, 02, has a rate constant of 4.9 X 10 4 s 2 at a certain temperature. Calculate the half-life of this reaction. 

In the Ostwald process ammonia is catalytically oxidized in a heterogeneous reaction. The key steps in the process are 1) Oxidation of ammonia to nitric oxide (NO), 2) Oxidation of NO to nitrogen dioxide (NO2) and 3) Absorption ofN02 in water to produce nitric acid. These steps are summarized in the following sections91,97. 

Tn the presence of sunlight and oxides of nitrogen (NOa,), hydrocarbons react to form new products, some of which are called oxidants. The most commonly investigated photochemically produced oxidants in the urban atmosphere are ozone (O3), nitrogen dioxide (NO2), and peroxy-acetylnitrate (PAN). 

In addition to being a key player in the CO and CH4 oxidation chains leading to the chemical production of O3 in the troposphere, NO also leads to the chemical production of HNO3, the fastest growing component of acidic precipitation. NO is chemically transformed to nitrogen dioxide (NO2) and then to NO via the following reactions ... 

Ammonia can react with oxygen in the presence of a hot catalyst to make nitric oxide (NO) and water. The NO reacts with further oxygen to make nitrogen dioxide (NO2) and this, when dissolved in water in the presence of oxygen, makes nitric acid. Write out the balanced equations, and explain the reactions in terms of redox processes. 

The effect of temperature on the gas-phase equilibrium of nitrogen dioxide, NO2, and dinitrogen tetroxide, N2O4, can be seen because of the difference in color of NO2 and N2O4. The intense brown NO2 gas is the pollution that is responsible for the colored haze that you sometimes see on smoggy days. 

Another way to determine the instantaneous rate for a chemical reaction is to use the experimentally determined rate law, given the reactant concentrations and the specific rate constant for the temperature at which the reaction occurs. For example, the decomposition of dinitrogen pentoxide (N2O5) into nitrogen dioxide (NO2) and oxygen (O2) is given by the following equation. 

Burning a compound of calcium, carbon, and nitrogen in oxygen in a combustion train generates calcium oxide (CaO), carbon dioxide (CO2), nitrogen dioxide (NO2), and no other substances. A small sample gives 2.389 g CaO, 1.876 g CO2, and 3.921 g NO2. Determine the empirical formula of the compound. 

This effect is illustrated by the equilibrium between nitrogen dioxide (NO2) and its dimer, dinitrogen tetraoxide (N2O4) (briefly considered in Example 9.6) expressed by the chemical equation... 

Chauhan AJ, Krishna MT, Frew AJ, Holgate ST Exposure to nitrogen dioxide (NO2) and respiratory disease risk. Rev Environ Health 1998 13 73-90. 

The oxidation of nitric oxide, firstly to nitrogen dioxide NO2 and ultimately... 

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... 

In the gas phase, nitrogen dioxide is actually a mixture of nitrogen dioxide (NO2) and dinitrogen tetrox-ide (N2O4). If the density of such a mixture is 2.3 g/L at 74°C and 1.3 atm, calculate the partial pressures of the gases and Kp for the dissociation of N2O4. 

Nitrogen dioxide (NO2) and ozone (O3). Concentrations of NO2 and O3 were in the range of 1.5-27.0 and 0.1-11.0 respectively. These levels are well below... 

The photolysis of nitrate and nitrite in sea water produces nitrogen dioxide (NO2) and nitric oxide (NO), respectively (eqns [I] and [II]). Previous work indicated that the photolysis of nitrite could act as a small net source of NO to the marine atmosphere under some conditions. However, this conclusion seems to be at odds with estimates of the steady-state concentrations of superoxide and the now known rate constant for the reaction of superoxide with nitric oxide (6.7 x 10 M s ) to form peroxyni-trite in aqueous phases (eqn [V]). 

Consider, the decomposition of dinitrogen pentoxide (N2O5) into nitrogen dioxide (NO2) and oxygen (O2), which proceeds as follows. 

In the upper atmosphere, ozone (O3) blocks harmful UV radiation. At the ground level, however, O3 is hazardous to our health. It is not emitted directly into the atmosphere through the consumption of energy. Rather, it is created by atmospheric reactions with nitrogen oxides and hydrocarbons, in particular, VOCs. In the absence of VOCs in the atmosphere, the amount of nitrogen dioxide (NO2) and O3 in the lower atmosphere are kept in check ... 

The final result of this react ion is the transformation of three oxygen molecules. O, into two ozone molecules, Oj. While there is no net consumption or production of the nitrr en monoxide. NO, nitrogen dioxide, NO2. and the atomic oxygen, O, species, only the nitrt en monoxide. NO. appears to be requited for this reaction to bt in. The nitrogen monoxide, NO, therefore, is best described as the catalyst. 

The principal atmospheric oxides of nitrogen include nitric oxide (NO), nitrogen dioxide (NO2), and nitrous oxide (N2O). Collectively, nitric oxide and nitrogen dioxide are connnonly referred to as NOx, which are generated by the reaction of the nitrogenous compounds of the coal and nitrogen in... 

Nitric acid (HNO3) can be produced by the reaction of nitrogen dioxide (NO2) and water. Nitric oxide (NO) is also formed as a product. Write a balanced chemical equation for this reaction. 

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