Per mole of the reaction

The per mole in the unit for AH means that this is the enthalpy change per mole of the reaction (or process) as it is written that is, when 1 mole of ice is converted to 1 mole of liquid water. 

In Sample Exercise 19.10 we calculated AG for this reaction AG = —33.3 kj. We will have to make some changes to the units of this quantity in applying Equation 19.21, however. In order for the units to match correctly, we will use AG in units of kj/mol. We will use "per mole" to mean "per mole of the reaction as written." Thus, we will use AG = -33.3 kJ/mol,whichimpliespermoleofN2,perthreemolesofH2,andper two moles of NH3. We can now use Equation 19.21 to calculate AG for these nonstandard conditions ... 

We use dimensionless stoichiometric coefficients. One can think of the units of v, as moles of substance i per mole of reaction. The enthalpy change in Eq. (2.7-11) has the units of J mol (meaning joules per mole of the reaction as written). If all stoichiometric coefficients are doubled, AH for the reaction doubles. When we give a value of Afor a reaction, it is always for 1 mol of the reaction as the reaction equation is written. 

Energy of Activation (kcAL per mole) for THE Reaction of Axkyl Iodides with Pyridines ... 

J = the average diffusion current in microamperes during the life of the drop n = the number of faradays of electricity required per mole of the electrode reaction (or the number of electrons consumed in the reduction of one molecule of the electro-active species) ... 

The reaction rates in Equation (5.17) are positive and apply to the reaction. That is, they are the rates of production of (possibly hypothetical) components having stoichiometric coefficients of -bl. Similarly, the heats of reaction are per mole of the same component. Some care is needed in using literature values. See Section 7.2.1. 

Ueno et al. [172] observed that CuInSe2/Ti with a composition close to the stoichiometric ratio (slight excess of metallic components) could be deposited exclusively at a specific potential value (-0.8 V vs. SCE) from a pH 1 bath of uncom-plexed precursors at 50-55 A positive shift in the potential was seen to result in the co-deposition of a Cu3Sc2 phase (umangite), while a negative shift led to contamination by metallic indium. On the basis of measured electrolysis charge, the overall reaction of the optimum cathodic process was considered to involve the transfer of 13 electrons per mole of the product ... 

The heat of hydrogenation of cyclohexene is about -120 kJ/mol (kilojoules per mole). If the reaction of one double bond releases this amount of energy, then the reaction of two double bonds (1,3-cyclohexadiene) should release about twice this cimount of energy. The classical, three double-bond benzene should... 

These values of A Hr are standard state enthalpies of reaction (aU gases in ideal-gas states) evaluated at 1 atm and 298 K. 7VU values of A are in kilojoules per mole of the first species in the equation. When A Hr is negative, the reaction hberates heat, and we say it is exothermic, while, when A Hr is positive, the reaction absorbs heat, and we say it is endothermic. Tks Table 2-2 indicates, some reactions such as isomerizations do not absorb or liberate much heat, while dehydrogenation reactions are fairly endothermic and oxidation reactions are fairly exothermic. Note, for example, that combustion or total oxidation of ethane is highly exothermic, while partial oxidation of methane to synthesis gas (CO + H2) or ethylene (C2H4) are only slightly exothermic. 

We also studied the effect of catalyst concentration on the reaction and determined that the reaction could take place without catalysis, but that its speed was highly dependent upon the concentration of catalyst, both in the case of 72% perchloric acid and in the case of the boron trifluoride etherate. A workable level for the perchloric acid catalyst was found to be in the order of 3-4 grams per mole of the acid-ester charge. A catalyst level for the boron trifluoride etherate of 40 grams per mole of the acid component charge was satisfactory. 

The catalytic activity, represented by the rate of evolution of the heat of reaction, is approximately the same for both catalysts when NiO(250) has converted 23.32 cc. per gram of the reaction mixture and NiO(200) has converted 5.69 cc. per gram (Figure 4B, curves C and B ). An even larger difference of activity is evident from curves C and C, both of which represent a steady value of the activity. The heat of reaction of doses C and C on both catalysts is close to 68 kcal. per mole (20). 

The sum of the weight (per mole) of the products is 0.0246 g less than the sum of the weights of the reactants. In the Bethe cycle (the series of reactions in the sun by which solar energy is produced), 4 moles of protons weighing 4.03228 g are converted to 1 mole of helium weighing 4.00336 g, a loss of 0.02892 g. In the nuclear fission of 2jji U,... 

When electrons flow in the external circuit the maximum amount of work that can be done per mole of electrochemical reaction (-AG) is given by Eq. 6-63... 

Calculate AH0 values for the following reactions in the gas phase per mole of the principal reactants, using the bond-energy table (Table 4-3). 

The standard enthalpy of formation, AHf°, of a substance is the standard reaction enthalpy for the formation of a substance from its elements in their most stable form. (Phosphorus is an exception white phosphorus is used because it is much easier to obtain pure than the other, more stable allotropes.) Standard enthalpies of formation are expressed in kilojoules per mole of the substance (kj-mol-1). We obtain AHf for ethanol, for instance, from the thermochemical equation for its formation from graphite (the most stable form of carbon) and gaseous hydrogen and oxygen ... 

Although the graft copolymer was obtained readily by the reaction of cw-1,4-polybutadiene with PVC in the presence of EtoAlCl alone, the addition of 0.001-0.1 mole of a cobalt compound per mole of the Et2AlCl yielded a gel-free product with superior properties. The preferred cobalt compound concentration was between 0.002 and 0.01 mole per mole of aluminum compound. The effective cobalt compounds were those generally used in polymerizing butadiene to cw-1,4-polybutadiene using the Et2AlCl-cobalt compound catalyst system. 

The preparation of the liquid ammonia solution of potassium amide, and the experiments themselves, have been described in detail elsewhere (Shatenshtein and Izrailevich, 1952, 1954a Shatenshtein et al., 1960). All the substances under investigation, except for saturated hydrocarbons, are soluble in liquid ammonia. The samples employed in the experiments were of the order of a few tenths of a gramme, and 50-200 moles of ammonia were used per mole of the substance. The absence of unwanted chemical reactions was checked by measuring the... 

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