Stoichiometrically equivalent molar ratios

The catalyst deactivation studies described here were carried out in 300 cm.. gas-sparged, stirred autoclaves and in a nominal 10 ton (CH30H)/day pilot-plant, bubble-column reactor. The details of the design and operation of these reactor systems have been reported elsewhere [refs. 4,5]. AH of the present studies were carried out with a feed gas that is referred to as "CO-Rich Gas , with a molar composition of H2 35%, CO-51 %, C02-13% and N2 1%- Its stoichiometric ratio, defined as H2/(CO+1.5002), is 0.5. A typical stoichiometric ratio for the feed to a conventional methanol reactor Is about 2.6, well on the H2-rich side of 2.0, the ratio tor exact stoichiometric equivalence. The feed concentrations of known poisons such as hydrogen sulfide, carbonyl sulfide, chlorine compounds, iron carbonyl and nickel carbonyl were below the limits of detection, 50 ppb, 50 ppb, 10 ppb, 50 ppb and 50 ppb, respectively. 

Stoichiometrically Equivalent Molar Ratios from the Balanced Equation... 

In a balanced equation, the number of moles of one substance is stoichiometrically equivalent to the number of moles of any other substance. The term stoichiometrically equivalent means that a definite amount of one substance is formed from, produces, or reacts with a definite amount of the other. These quantitative relationships are expressed as stoichiometrically equivalent molar ratios that we use as conversion factors to calculate these amounts. Table 3.3 presents the quantitative information contained in the equation for the combustion of propane, a hydrocarbon fuel used in cooking and water heating ... 

Here s a typical problem that shows how stoichiometric equivalence is used to create conversion factors in the combustion of propane, how many moles of O2 are consumed when 10.0 mol of H2O are produced To solve this problem, we have to find the molar ratio between O2 and H2O. From the balanced equation, we see that for every 5 mol of O2 consumed, 4 mol of H2O is formed ... 

Up until now, we ve been optimistic about the amount of product obtained from a reaction. We have assumed that 100% of the limiting reactant becomes product, that ideal separation and purification methods exist for isolating the product, and that we use perfect lab technique to collect all the product formed. In other words, we have assumed that we obtain the theoretical yield, the amount indicated by the stoichiometrically equivalent molar ratio in the balanced equation. 

The substances in a balanced equation are related to each other by stoichiometrically equivalent molar ratios, which can be used as conversion factors to find the moles of one substance given the moles of another. In limiting-reactant problems, the amounts of two (or more) reactants are given, and one of them limits the amount of product that forms. The limiting reactant is the one that forms the lower amount of product. In practice, side reactions, incomplete reactions, and physical losses result... 

In Chapters 3 and 4, we encountered many reactions that involved gases as reactants (e.g., combustion with O2) or as products (e.g., a metal displacing H2 from acid). From the balanced equation, we used stoichiometrically equivalent molar ratios to calculate the amounts (moles) of reactants and products and converted these quantities into masses, numbers of molecules, or solution volumes (see Figure 3.10). Figure 5.11 shows how you can expand your problem-solving repertoire by using the ideal gas law to convert between gas variables (F, T, and V) and amounts (moles) of gaseous reactants and products. In effect, you combine a gas law problem with a stoichiometry problem it is more realistic to measure the volume, pressure, and temperature of a gas than its mass. 

Just as we use stoichiometrically equivalent molar ratios to find amounts of substances, we use thermochemically equivalent quantities to find the heat of reaction for a given amount of substance. Also, just as we use molar mass (in g/mol of substance) to convert moles of a substance to grams, we use the heat of reaction (in kJ/mol of substance) to convert moles of a substance to an equivalent quantity of heat (in kJ). Figure 6.9 shows this new relationship, and the next sample problem applies it. 

The second way we used excitation spectra was to follow the changes in excitation maxima as a function of the molar ratio of the poly(carboxylic acid) to the PEG (41). We observed that the initial red shift of the excimer excitation spectrum relative to the monomer for Py-PEG-Py(4800) remained approximately constant as the PAA(890,000) content was increased. There was, however, an enhancement in the relative shift of the excimer for PMAA(9500) up to the stoichiometric equivalence of PMAA to PEG. Thereafter, the shift between excimer and monomer remained constant. One form of comparison of these results is shown in Figure 3, where we present the monomer excitation spectra for Py-PEG Py(4800) free in aqueous solution and complexed with PMAA(9200) at [PMAA] to [PEG] ratio of 5 1. 

Traditionally, phosphate esters are prepared by the reaction of phosphoric anhydride with an alcohol or alcohol ethoxylate [23-26]. The reaction, when stoichiometric proportions of 6 moles of alcohol per mole of P4O10 (four equivalents of phosphorus) are used, theoretically produces a 50 50 molar ratio of MAP and DAP. These mixtures are frequently referred to as sesquiphosphates. 

The substances in a balanced equation are related to each other by stoichiometrically equivalent molar ratios, which are used as conversion factors to find the amount (mol) of one substance given the amount of another. 

Stoichiometrically Equivalent Molar Ratios from the Balanced Equation 89 Reactions That Involve a Limiting Reactant 93... 

Per equation 9-68, two moles of Fe are required per mole of HS , or, equivalently, per mole of absorbed H2S. In the LO-CAT and Autocirculation LO-CAT processes, the molar ratio of iron in the scrubbing solution to H2S in the feed gas is typically 4 1, twice the stoichiometric requirement (Hardison, 1992). In the LO-CAT II process (both the conventional and Autocirculation versions), this ratio is typically less than 2 1. 

FAR or AFR. The composition of a mixture of fuel and air or oxidant is often specified according to the Fuel to Air Ratio (FAR), and can be expressed on a mass, molar, or volume basis. The FAR is normalized to the stoichiometric composition by defining the equivalence ratio ( ) as in equation 1, where = mass of fuel, kg and = mass of oxidizer, kg. 

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