Molar concentration of gas

CTOT total molar concentration of gas phase (niol/mgfls3)... 

Of course, you should be familiar with this equation (the Ideal Gas Law), where n is the molar concentration of solute, R is the universal gas law constant, and T is absolute temperature in °K. The permeate flow can be calculated from ... 

For example, in the case of dilute solutions, the van t Hoff s equation may be used to piedict the osmotic pressure (jr = CRT) where n is the osmotic pressure of the solution, C is the molar concentration of the solute, ft is the universal gas constant and T is the absolute temperature, Fm dissociating solutes, the concentration is that of the total ions. For example, NaCI dissociates in water into two ions Na" " and Cl . Therefore, the total molar concentration of ions is hvice the molar concentration of NaCI. A useful rule of thumb for predicting osmotic pressure of aqueous solutions is 0,01 psi/ppm of solute (Weber, 1972). 

FIGURE 5.10 Effects of co-expressed G-protein (G ) on neuropeptide NPY4 receptor responses (NPY-4). (a) Dose-response curves for NPY-4. Ordinates Xenopus laevis melanophore responses (increases light transmission). Ordinates logarithms of molar concentrations of neuropeptide Y peptide agonist PYY. Curves obtained after no co-transfection (labeled 0 jig) and co-transfection with cDNA for Gai6. Numbers next to the curves indicate jig of cDNA of Ga]g used for co-transfection, (b) Maximal response to neuropeptide Y (filled circles) and constitutive activity (open circles) as a function of pg cDNA of co-transfected G g. 

According to Maxwell s law, the partial pressure gradient in a gas which is diffusing in a two-component mixture is proportional to the product of the molar concentrations of the two components multiplied by its mass transfer velocity relative to that of the second component. Show how this relationship can be adapted to apply to the absorption of a soluble gas from a multicomponent mixture in which the other gases are insoluble and obtain an effective diffusivity for the multicomponent system in terms of the binary diffusion coefficients. 

As we saw in Section G, the molar concentration of any substance is the amount of molecules (n, in moles) divided by the volume that they occupy (V). It follows from the ideal gas law that, for a gas behaving ideally (so we can write n = PV/RT),... 

Hydrogen bums in an atmosphere of bromine to give hydrogen bromide. If 135 mL of H, gas at 273 K and LOO atm combines with a stoichiometric amount of bromine and the resulting hydrogen bromide dissolves to form 225 mL of an aqueous solution, what is the molar concentration of the resulting hydrobromic acid solution ... 

In the model equations, A represents the cross sectional area of reactor, a is the mole fraction of combustor fuel gas, C is the molar concentration of component gas, Cp the heat capacity of insulation and F is the molar flow rate of feed. The AH denotes the heat of reaction, L is the reactor length, P is the reactor pressure, R is the gas constant, T represents the temperature of gas, U is the overall heat transfer coefficient, v represents velocity of gas, W is the reactor width, and z denotes the reactor distance from the inlet. The Greek letters, e is the void fraction of catalyst bed, p the molar density of gas, and rj is the stoichiometric coefficient of reaction. The subscript, c, cat, r, b and a represent the combustor, catalyst, reformer, the insulation, and ambient, respectively. The obtained PDE model is solved using Finite Difference Method (FDM). 

Let us say that this new surface equilibrium temperature of the water is 15.5 °C then the vapor pressure is 0.0174 atm. At the surface of the water, not only does water vapor exist, but so must the original gas mixture components of air, O2 and N2. By Dalton s law the molar concentration of the water vapor is... 

CAe Molar concentration of A in liquid phase in equilibrium with partial pressure Pag in gas phase kmol/m3 NL-3... 

Here Dq and Dl are the diffusivities of A in the gas phase and the coating liquid, respectively, and is the total molar concentration of the shell phase. 

The osmotic pressure, at constant temperature, of a dilute solution is proportional to the concentrations of the dissolved substances i.e., U = RTXc, where II is the osmotic pressure, R is the molar gas constant, T is the absolute temperature and Ci is the molar concentration of species i. 2. In stereochemistry, all optically active molecules contain one or more multivalent atoms united... 

The process of hydration of an ion refers to the conversion of one mole of the gaseous ions under standard conditions at a pressure of I bar to the hydrated ions at a molar concentration of 1 mol dm-3. The process may be divided into two parts. These are the compression of the one mole of gaseous ions into a volume of 1 dm3 followed by the interaction of the ions with water to produce the hydrated ions. Assuming ideal gas behaviour, the compression of one mole of a gas at standard pressure and at 298.15 K into a volume of I dm3 requires the expenditure of enthalpy given by RT ln(24.79/l. 0) = +7.96 kJ mol -. The quoted values of ionic hydration enthalpies include a contribution from the compression of the gaseous ions and the enthalpy changes associated with the hydration process are given by the equation ... 

C = liquid-phase molar concentration of cesium D — liquid-phase diffusivity of cesium Dv = gas-phase diffusivity f = fractional release J = mass flux... 

Here [A] is the gas-phase molar concentration of A above the surface, for example, in mol/cm3. Assuming that the total site density T is fixed and that the surface population consists of either adsorbed species A(s) or open sites O(s),... 

First kLa is determined from an instantaneous reaction. Then kD from a fast reaction using the known kLa. In order to avoid the influence of the gas-side resistance the experiments have to be conducted with an initial molar concentration of pollutant M far below the solubility level of ozone (related to the input gas concentration respectively the ozone partial pressure). In the study of Beltran and Alvarez (1996) an instantaneous reaction of ozone and phenol developed with c(M)t, < 0.5 mM and p(02) > 500 Pa = 6.1 mmol L 1 gas (T = 20 °C). All parameters were held constant while testing pairs of c(M)n andp(03), for which the concentration change over time was measured. The instantaneous kinetic regime must be verified for each run (Beltran and Alvarez, 1996). 

First, we express Kc in terms of the volume of the system. The molar concentration of each gas is the amount, n, of that gas divided by the volume, V, of the reaction vessel ... 

Techniques used to study fast reactions all monitor concentration spectroscopically, as described in Major Technique 2. For instance, suppose we were studying the effect of a chlorofluorocarbon on the concentration of ozone, a blue gas. We could use a spectrometer to monitor the absorption responsible for the color and interpret the intensity of absorption in terms of the molar concentration of 03 molecules. In the stopped-flow technique, solutions of the reactants are forced into a mixing chamber very rapidly and the formation of products is observed spectroscopically (Fig. 13.3). This procedure is commonly used to study biologically important reactions. 

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