Ammonia heat capacity ratio

When actual data are not available, a useful approximate rule for ordinary temperatures and pressures, is to take y as 1.67 for monatomic gases, 1.40 for diatomic gases, 1.30 for simple polyatomic gases, such as water, carbon dioxide, ammonia and methane. It may be noted that the heat capacity ratio for hydrogen gas increases at low temperatures toward the vfdue for a monatomic gas. This matter will be explained in Chapter VI. 

Heat capacity ratio, k = Cp/c, = 1.04 for gases with molar mass > 100. The value of k increases to 1.67 as the molar mass decreases. For air =1.4 and for such gases as ethylene, carbon dioxide, steam, sulfur dioxide, methane, ammonia = 1.2-1.3. Temperature rise between feed 1 and exit 2 ... 

Ratio of specific heat capacities (Cp/C ) = 1.33 Molecular weight of ammonia = 17.03... 

By employing 7.5 parts of 28 per cent ammonia liquor per part of 2-chloroanthraquinone (molar ratio 25 1) and heating at 200 C, the reactions can be completed in 24 hr at 2iO C, only 15 hr is required. It is advisable to fill the autoclave up to 75 per cent of its capacity with the aqueous ammonia in order to ensure against excestive freeboard. 

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