Oxygen balance equation

Bennett, J.P. 1971. Convolution approach to the solution for the dissolved oxygen balance equation in a stream. Water Resour. Res. 7 530-590. 

The distribution of oxygen in the tank is finally computed with the aid of numerical simulations of the oxygen balance equation (Figure 3.17) ... 

As an oxygen balance close to zero remains a strong requirement for new propellants, the search for such compounds has been fruitful and new EILs have been proposed (Christe Drake, 2003 Jones et al., 2006 Tao et al., 2008) and some examples are presented in Fig. 8. Table 2 presents the corresponding oxygen balance values for the formation of CO2 and CO. As an example, the oxygen balance equation for 1 (Fig. 8), based on CO formation is ... 

Write a balanced equation for the reduction of molecular oxygen by reduced cytochrome e as carried out by complex IV (cytochrome oxidase) of the electron transport pathway. 

One molecule (or mole) of propane reacts with five molecules (or moles) of oxygen to produce three molecules (or moles) or carbon dioxide and four molecules (or moles) of water. These numbers are called stoichiometric coefficients (v.) of the reaction and are shown below each reactant and product in the equation. In a stoichiometrically balanced equation, the total number of atoms of each constituent element in the reactants must be the same as that in the products. Thus, there are three atoms of C, eight atoms of H, and ten atoms of O on either side of the equation. This indicates that the compositions expressed in gram-atoms of elements remain unaltered during a chemical reaction. This is a consequence of the principle of conservation of mass applied to an isolated reactive system. It is also true that the combined mass of reactants is always equal to the combined mass of products in a chemical reaction, but the same is not generally valid for the total number of moles. To achieve equality on a molar basis, the sum of the stoichiometric coefficients for the reactants must equal the sum of v. for the products. Definitions of certain terms bearing relevance to reactive systems will follow next. 

Reality Check Notice that the concentration of 02, a product in the reaction, appears in the denominator. The rate is inversely proportional to the concentration of molecular oxygen, a feature that you would never have predicted from the balanced equation for the reaction. As the concentration of 02 builds up, the rate slows down. 

Dinitrogen pentoxide gas decomposes to form nitrogen dioxide and oxygen. The reaction is first-order and has a rate constant of 0.247 h1 at 25°C. If a 2.50-L flask originally contains N205 at a pressure of 756 mm Hg at 25°C, then how many moles of 02 are formed after 135 minutes (Hint. First write a balanced equation for the decomposition.)... 

Write balanced equations for the reaction of (a) sodium with hydrogen. (b) barium with oxygen. 

If we start with hydrogen and oxygen, equilibrium is attained after most of the hydrogen and oxygen have united to form water. More important, though, the partial pressures at equilibrium are the same as those obtained beginning with pure H20. The equilibrium pressures are fixed by the temperature, the composition, and the total pressure they do not depend upon the direction from which equilibrium is approached. The balanced equation does not indicate the concentrations (or partial pressures) at equilibrium. 

The requirement for oxygen and carbon source for cell biosynthesis are calculated using nitrogen-limited mass balance equations for growth during exopolysaccharide production 01 res (nitrogen-limited cultures). These balances are derived from experimentally determined values of ... 

Dividing the oxygen balance by the volume of the aeration tank and concentration of biomass, XV, the above equation will be simplified as follows ... 

Except for oxygen-balanced expls, the computation of detonation products depends strongly on the choice of the equation of state (EOS) for these products. In the US the BKW EOS (see Vol 4, D272-R) has been favored and most of the computed product compns below will be based on it. Some of these will be compared with the relatively few calcns based on a Lennard-Jones-Devonsnire (UD) EOS (see Voi 4, D287-L)... 

Sometimes we need to construct a balanced chemical equation from the description of a reaction. For example, methane, CH4, is the principal ingredient of natural gas (Fig. H.3). It burns in oxygen to form carbon dioxide and water, both formed initially as gases. To write the balanced equation for the reaction, we first write the skeletal equation ... 

H. 10 An important role of stratospheric ozone, Os, is to remove damaging ultraviolet radiation from sunlight. One result is the eventual dissociation of gaseous ozone into molecular oxygen gas. Write a balanced equation for the dissociation reaction. 

H.12 The reaction of boron trifluoride, BF,(g), with sodium borohydride, NaBH4(s), leads to the formation of sodium tetrafluoroborate, NaBF4(s), and diborane gas, B2Hfc(g). The diborane reacts with the oxygen in air, forming boron oxide, B20 j(s), and water. Write the two balanced equations leading to the formation of boron oxide. 

H.15 Write a balanced equation for the complete combustion (reaction with oxygen) of liquid heptane, C7H)6, a component typical of the hydrocarbons in gasoline, to carbon dioxide gas and water vapor. 

H.17 The psychoactive drug sold as methampheramine ( speed ), CI0H,N, undergoes a series of reactions in the body the net result of these reactions is the oxidation of solid methamphetamine by oxygen gas to produce carbon dioxide gas, liquid water, and nitrogen gas. Write the balanced equation for this net reaction. 

H.20 The first stage in the production of nitric acid by the Ostwald process is the reaction of ammonia gas with oxygen gas, producing nitric oxide gas, NO, and liquid water. The nitric oxide further reacts with oxygen to produce nitrogen dioxide gas, which, when dissolved in water, produces nitric acid and nitric oxide. Write the three balanced equations that lead to the production of nitric acid. 

Aniline, C6H5NH2(1), is a derivative of benzene in which a hydrogen atom has been replaced by an NH2 group, (a) Write the balanced equation for the combustion of aniline, (b) What is the mass of each product when 0.1754 g of aniline is burned in excess oxygen (c) If the bomb calorimeter in which this reaction was carried out had a volume of 355 mL, what minimum pressure of oxygen at 23°C must have been used to ensure complete combustion Assume that the volume of the aniline is negligible. 

Using data available in Appendix 2A, write balanced equations and calculate the hear released when (a) 1.00 mol and (b) 1.00 g of each of the following compounds is burned in excess oxygen propane, butane, and pentane. Is there a trend in the amount of heat released per mole of molecules or per gram of compound If so, what is it ... 

Solution The initial liquid-phase concentration of oxygen is 0.219mol/m as in Example 11.1. The final oxygen concentration will be 1.05 mol/m. The phase balances. Equations (11.11) and (11.12), govern the dynamic response. The flow and reaction terms are dropped from the liquid phase balance to give... 

Ammonium nitrate, a colorless Ionic solid used as a fertilizer, explodes when it is heated above 300 °C. The products are three gases molecular nitrogen, molecular oxygen, and steam (water vapor). Write a balanced equation for the explosion of ammonium nitrate. 

Acrylonitrile Is produced from propene, ammonia, and oxygen by the following balanced equation (see Example 14-5) 2 C3 Hg + 2 NH3 + 3 O2 2 CH2 CHCN -1- 6 H2 O Relate the rates of reaction of starting materials and products. 

The balanced equation shows that three molecules of oxygen are consumed for every two molecules of propene and two molecules of ammonia. Thus, the rate of C3 Hg and NH3 consumption is only two-thirds the rate of O2 consumption. Those seven molecules of starting materials produce two molecules of CH2 CHCN and six molecules of H2 O. Thus, CH2 CHCN is produced at the same rate as C3 Hg is consumed, whereas H2 O is produced three times as fast as CH2 CHCN is. The link between relative reaction rates and reaction stoichiometry is Equation. Therefore,... 

The oxygen balance is, when negative, the quantity of oxygen internal to the molecule that is missing to ensure complete oxidation of this molecule, z is given directly by the coefficient of O2 in the equation of combustion. 

One has to be careful, however, in defining time constants. The first important step is to set up the correct equations appropriately. If the prime interest is not the accumulation of oxygen in the liquid as defined previously, but the depletion of oxygen from the gas bubbles, then the appropriate balance equation becomes... 

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