Mass relations

A conservation of mass relates the moles of Fe + to the moles of FeyOy Moles Fe + = 2 X moles FeyOy... 

The general topic of this chapter is stoichiometry (stoy-key-OM-e-tree), the study of mass relations in chemistry. Whether dealing with atomic masses (Section 3.1), molar masses (Section 3.2), chemical formulas (Section 3.3), or chemical reactions (Section 3.4), you will be answering some very practical questions that ask how much or how many—." For example—... 

Given a pair of elements and their mass relation, answer die following questions. 

The approach followed in Chapter 3 to calculate mole-mass relations in reactions is readily applied to solution reactions represented by net ionic equations. 

Clausius-Clapeyron, 230,303-305 Gibbs-Helmholtz, 459,461 Henderson-Hasselbalch, 79-80 mass relation, 62-63 Nemst, 493-494 net ionic, 79-80 nonmetals, 575q nuclear, 513,530-531q Planck s, 135 redox, balancing, 90-92 Schrodinger, 140 thermochemical, 204... 

Formula An expression used to describe the relative numbers of atoms of different elements present in a substance, 34 mass relations in, 69-70q nonmetals, 575q... 

By working parts (a) through (d) of this sample in succession, you can see how many different ways there are to ask a question about mass relations in a reaction. That should cushion the shock should you see only part (d) in an exam. 

The parts of the Graded Example do not just progress from an easy mass relations question to a more difficult one. The value of the Graded Example is that the last question assumes the ability to answer the earlier ones. You may be able to answer parts (a) and (b) with a limited understanding of the material, but to answer part (d) you need to have mastered the material. 

In order to use Eqs. (3) and (4) or the data given in Fig. 1, for the calculation of maximum turbulent fluctuation velocity the maximum energy dissipation e , must be known. With fully developed turbulence and defined reactor geometry, this is a fixed value and directly proportional to the mean mass-related power input = P/pV, so that the ratio ,/ can be described as an exclusive function of reactor geometry. In the following, therefore details will be provided on the calculation of power P and where available the geometric function ,/ . 

Fig. 15. Reference floe diameter dp for bubble columns versus mass related adiabatic compressor power PJqV...

The ideal gas equation can be combined with the mole-mass relation to find the molar mass of an unknown gas PV = nRT (ideal gas equation) and n — (mole-mass relation) if we know the pressure, volume, and temperature of a gas sample, we can use this information to calculate how many moles are... 

Whereas liquids and solids have well-defined densities, the density of a gas varies strongly with the conditions. To see this, we combine the ideal gas equation and the mole-mass relation and rearrange to obtain an equation for... 

Yield and other mass-related metrics such as atom economy, reaction mass efficiency and mass intensity have been examined by Constable et al with regard to their significance concerning greenness and costs. The importance of using a (product) concentration term, which can be mass intensity or mass index, is additionally emphasized by Laird et al This is in compliance with Winterton, who in his twelve more green chemistry principles demands the establishment of full mass balances. 

The mass-related metrics shown in Figure 5.11 indicate that the amount of a substrate (see also byproduct formation), an auxiliary material for reaction, and of a solvent have to be reduced. The detailed view of the mass indices of the pilot scale, for example, the segments Substrates and Aux (R) and the size of segments Substrates (excess) and Aux (R) of the environmental factor E, deliver the information listed in Table 5.2 108% base and 162% auxiliary (R) are used. The measure to increase base addition for recycling purposes was successful at the expense of 193% base, much auxiliary material Aux (R) was saved in operation scale (reduction from 162% to only 13%). This leads to an overall... 

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