Hydrogen with nitrogen monoxide

Had the reaction occurred in dilute nitric acid, the product nitrogen dioxide, NOz, would be replaced with nitrogen monoxide, NO. Notice that this is not a typical replacement, where hydrogen gas is released. These gases are characteristic of the reaction. If sulfuric acid was used instead of nitric acid, the gas would be SOz. 

The basic synthetic process is the Haher-Bosch method. As presented in Fig. 32.2, ammonia is produced by the reversible reaction of hydrogen with nitrogen. The reactants mixture, often called the synthesis gas, consists of hydrogen and nitrogen in roughly 3 1 molar ratio and impurities such as argon, methane, carbon dioxide, carbon monoxide, and water vapor. Nitrogen is separated from the air. 

Hydrogen gas reacts with nitrogen monoxide gas at constant volume and at an elevated constant temperature, via the following equation. 

Similarly, the reaction between hydrogen and nitrogen monoxide has been experimentally determined to be first order with respect to hydrogen, second order with respect to nitrogen monoxide, and thus third order overall. 

As an example, consider the reaction by which hydrogen reacts with nitrogen monoxide to form water and nitrogen gas ... 

Acrylonitrile is combustible and ignites readily, producing toxic combustion products such as hydrogen cyanide, nitrogen oxides, and carbon monoxide. It forms explosive mixtures with air and must be handled in weU-ventilated areas and kept away from any source of ignition, since the vapor can spread to distant ignition sources and flash back. 

The combustible components of the gas are carbon monoxide and hydrogen, but combustion (heat) value varies because of dilution with carbon dioxide and with nitrogen. The gas has a low flame temperature unless the combustion air is strongly preheated. Its use has been limited essentially to steel (qv) mills, where it is produced as a by-product of blast furnaces. A common choice of equipment for the smaller gas producers is the WeUman-Galusha unit because of its long history of successful operation (21). 

In the gas phase, methylene chloride reacts with nitrogen dioxide at 270°C to yield a gaseous mixture consisting mainly of carbon monoxide, nitric oxide, and hydrogen chloride (8). 

Figure 14. Flammable limits for hydrogen, carbon monoxide, methane, with nitrogen, carbon dioxide and water vapor.

Type 66 nylon is a polyamide first commercialized by DuPont just prior to World War II. At that time, the needed hexamethylenediamine was made from adipic acid by reaction with ammonia to adiponitrile followed by reaction with hydrogen. The adipic acid then, like now, was made from cyclohexane. The cyclohexane, however, was derived from benzene obtained from coal. The ammonia was made from nitrogen in the air by reaction with hydrogen from water obtained in the water-gas shift reaction with carbon monoxide from the coal. So, in the 1950s, nylon was honestly advertised by DuPont as being based on coal, air, and water. 

Ueda, A., Nakano, T., Azuma, M. et al. (1998) Two conversion maxima at 373 and 573K in the reduction of nitrogen monoxide with hydrogen over Pd/Ti02 catalyst, Catal. Today 45, 135. 

If the irradiated water was, however, saturated with hydrogen or carbon monoxide instead of oxygen then no oxides were formed [35]. Under these conditions reduction of nitrogen occurred to afford ammonia [36]. Interestingly, HCN is also observed when carbon monoxide is replaced by methane [37].Thus the result of a sonochemical reaction, in water, depends largely on the nature of the dissolved gases and their concentration. 

---