Calculations mass number

Nominal ion mass. The mass of an ion with a given empirical formula calculated using the integer mass numbers of the most abundant isotope of each element, e.g., C = 12, H = 1, O = 16. 

The main objective for calculating the number of theoretical stages (or mass-transfer units) in the design of a hquid-liquid extraction process is to evaluate the compromise between the size of the equipment, or number of contactors required, and the ratio of extraction solvent to feed flow rates required to achieve the desired transfer of mass from one phase to the other. In any mass-transfer process there can be an infinite number of combinations of flow rates, number of stages, and degrees of solute transfer. The optimum is governed by economic considerations. 

The other common objective for calculating the number of countercurrent theoretical stages (or mass-transfer units) is to evaluate the performance of hquid-liquid extraction test equipment in a pilot plant or to evaluate production equipment in an industrial plant. Most liq-uid-hquid extraction equipment in common use can oe designed to achieve the equivalent of 1 to 8 theoretical countercurrent stages, with some designed to achieve 10 to 12 stages. 

The concept of a mass-transfer unit was developed many years ago to represent more rigorously what happens in a differential contactor rather than a stagewise contactor. For a straight operating line and a straight equilibrium line with an intercept of zero, the equation for calculating the number of mass-transfer units based on the overall raffinate phase N r is identical to the Kremser equation except for the denominator when the extraction factor is not equal to 1.0 [Eq. (15-23)]. 

The data for a plot like Fig. 18-60 are easily obtained from a screen analysis of the total crystal content of a known volume (e.g., a liter) of magma. The analysis is made with a closely spaced set of testing sieves, as discussed in Sec. 19, Table 19-6, the cumulative number of particles smaller than each sieve in the nest being plotted against the aperture dimension of that sieve. The fraction retained on each sieve is weighed, and the mass is converted to the equivalent number of particles by dividing by the calculated mass of a particle whose dimension is the arithmetic mean of the mesh sizes of the sieve on which it is retained and the sieve immediately above it. 

One way of calculating the number of equilibrium stages (or number of theoretical plates, NTP) for a mass exchanger is the graphical McCabe-Thiele method. To illustrate this procedure, let us assume that over the operating range of compositions, the equilibrium relation governing the transfer of the pollutant from the... 

Transport numbers are intended to measure the fraction of the total ionic current carried by an ion in an electrolyte as it migrates under the influence of an applied electric field. In essence, transport numbers are an indication of the relative ability of an ion to carry charge. The classical way to measure transport numbers is to pass a current between two electrodes contained in separate compartments of a two-compartment cell These two compartments are separated by a barrier that only allows the passage of ions. After a known amount of charge has passed, the composition and/or mass of the electrolytes in the two compartments are analyzed. Erom these data the fraction of the charge transported by the cation and the anion can be calculated. Transport numbers obtained by this method are measured with respect to an external reference point (i.e., the separator), and, therefore, are often referred to as external transport numbers. Two variations of the above method, the Moving Boundary method [66] and the Eiittorff method [66-69], have been used to measure cation (tR+) and anion (tx ) transport numbers in ionic liquids, and these data are listed in Table 3.6-7. 

B Nicotine is a diamino compound isolated from dried tobacco leaves. Nicotine has two rings and M + = 162.1157 by high-resolution mass spectrometry. Give a molecular formula for nicotine, and calculate the number of double bonds. 

It is necessary to calculate mass transfer coefficients between a fluid and the surface of a particle in a number of important cases, including ... 

SOLUTION To calculate the number (N) of atoms in the sample, we divide the mass of the sample by the mass of one carbon atom, 1.99 X 10 26 kg, which was given in the text ... 

Fig. 13. Yields of nuclei in the fission of U230, as a function of mass number. The points are averages of reported experimental values, and the curve is the result of a simple theoretical calculation described in the text.

In POLYM the output data of KINREL are used with compositional information to calculate the number and mass average molecular masses (Rn and Rm, respectively) and number and end-group average functionalities (fp and fg> respectively) in the pre-gel region in all stages. In addition, the network characteristics such as sol fraction, mj, and the number of elastically active network chains per monomer (5), Ng, are calculated in the post-gel regime of stage 3. 

To determine the mass of NiCl2 6 H2 O required to prepare the solution, first calculate the number of moles of the salt required, and then use the molar mass to determine the mass in grams ... 

Use the molar mass of methane to calculate the number of moles ... 

The question asks for the mass of oxygen. We can use the ideal gas equation to calculate the number of moles of oxygen, and then molar mass leads us from moles to grams. 

From the mass of 100 mF of split peas and the mass of one split pea, calculate the number of split peas in 100 mF. 

In this activity, you will first standardize a NaOH solution by using the solution to titrate a known mass of oxalic acid (H2C204). Then, you will use your standardized solution to titrate a sample of vinegar. Vinegar is a solution of acetic acid (HC2H302). From your titration data, you will be able to calculate the number of moles and the mass of the acetic acid in your vinegar sample and determine the percent of acetic acid in vinegar. 

Atoms and their symbols were introduced in Chap. 3 and 1. In this chapter, the representation of compounds by their formulas will be developed. The formula for a compound (Sec. 4.3) contains much information of use to the chemist. We will learn how to calculate the number of atoms of each element in a formula unit of a compound. Since atoms are so tiny, we will learn to use large groups of atoms—moles of atoms—to ease our calculations. We will learn to calculate the percent by mass of each element in the compound. We will learn how to calculate the simplest formula from percent composition data, and to calculate molecular formulas from simplest formulas and molecular weights. The procedure for writing formulas from names or from knowledge of the elements involved will be presented in Chaps. 5. ft. and 13. 

The balanced equation expresses quantities in moles, but it is seldom possible to measure out quantities in moles directly. If the quantities given or required are expressed in other units, it is necessary to convert them to moles before using the factors of the balanced chemical equation. Conversion of mass to moles and vice versa was considered in Sec. 4.5. Here we will use that knowledge first to calculate the number of moles of reactant or product, and then use that value to calculate the number of moles of other reactant or product. 

Calculate the number of moles of NaOH required to remove the S02 from 10.0 metric tons (10.0xl06g) of atmosphere if the S02 is 0.10% by mass. (Na2S03 and water are the products.)... 

The value of n is not given explicitly in the problem, but the mass is given, with which we can calculate the number of moles ... 

Arts. From the pressure, volume, and temperature data, we can calculate the number of moles of gas present. From the number of moles and the mass, we can calculate the molecular weight. 

The major use of equivalents stems from its definition. Once you define the number of equivalents in a certain mass of a substance, you do not need to write the equation for its reaction. That equation has already been used in defining the number of equivalents. Thus, a chemist can calculate the number of equivalents in a certain mass of substance, and his technicians can subsequently use that definition without knowing the details of the reaction. 

Arts. (a) The difference is the mass of the electron, (b) The actual mass of an atom is nonintcgral. (Calculations involving mass, such as those using E = me2, should use the actual mass.) The mass number is an integer, equal to the number of protons plus neutrons in the nucleus. In this case, the mass number is 1. 

Ans. The number of alpha particles, calculated from the loss of mass number, is 8, because the mass number was lowered by 32. The number of beta particles is equal to twice the number of alpha particles minus the difference in atomic numbers of the two isotopes ... 

It has been hoped [20,21] that a method could be developed which would directly detect the radioatoms that are present in nature by an efficient ultra-sensitive mass spectrometer technique which would not itself depend upon the fact that the atoms being investigated are radioactive. The advantage of an efficient mass spectrometer system for long-lived radioisotopes can be seen from the equation for calculating the number of atoms present in a sample from its measured radioactive decay rate ... 

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