Molar conversions moles

Cross-sectional area Volumetric flow rate Reaction rate Stoichiometric constant Molar flow rate Molar feed flow rate A Molar feed flow rate B Molar inert flow rate Pressure Gas constant Temperature Fraction conversion Mole fraction Length... 

The conversion between molarity and mole fraction involves the density, p, of the solution and is (by calculating the mole fraction of 1 L of solution)... 

This value for total molar conversion, along with the initial moles of C2H2 and H2, now allows reaction time to be calculated. Since the initial mixture is 75% hydrogen and 25% acetylene, Nn2 0 = 3(0.001) = 0.003. Substituting into the design equation from step 2,... 

The units of molarity are mole/liter (of solution), but they are commonly replaced with a capital M, which symbolizes molarity. Yet, there will be times when you will need to replace M with mole/liter when analyzing units and solving problems. If a sodium hydroxide solution is labeled 2 M (read as two-molar), it means that 2 moles of NaOH are dissolved in 1 L of solution, 2 moles/liter. If you need to brush up on mass-mole conversions, review the pertinent material in Chapter 5. In all the problems dealing with molar solutions, molarity will be written as a conversion factor to emphasize the canceling and retention of units, just as was done with the percent concentrations. The molarity term for a solution that is 0.55 M in NaOH could be written in four ways to make the required conversion factor ... 

Fig. 7-3 Additional Conversions. Moles of a gas may be determined from other data, such as moles of another reagent in a chemical reaction or mass and molar mass. Conversely, these values may be determined from gas data by working in the opposite direction on the figure. Again, start with the data provided and work toward the answer required. (Remember the boy scouts.)... 

What does 1 ppm represent in terms of moles per liter It depends on the formula weight, but the approximate relationship between concentrations in parts per million (or parts per billion) and in moles per liter can be seen by assuming a formula weight of 100 for an analyte. Then, since 1 ppm = 10 g/L, it is equal to (10 g/L) (10 g/mol) = 10 mol/L. Similarly, 1 ppb = 10 mol/L. Note that this latter concentration is smaller than the hydrogen ion concentration in pure water (10" mol/L) Of course, this relationship is approximate and will vary with the formula weight. One part per million solutions of zinc and copper, for example, will not be the same molarity. Conversely, equal molar solutions of different species will not be equal in terms of ppm unless the formula weights are equal. The former concentration is based on the number of molecules per unit volume, while the latter is based on the weight of the species per unit volume. 

Measured molar fraction / mole % Figure 7.11 Comparison of calculations for and measurements at 45MPa, 450°C and water glycerol ratios between 131-199. The overall conversion and selected products are considered. 

Dimensional analysis can be used in this conversion if we express molarity as moles/liter soln. To obtain moles, therefore, we multiply liters and molarity moles = liters X molarity. 

Conv. GLY, glycerol conversion sel. DHA, selectivity to dihydroxyacetone yield DHA, molar yield (%) [moles of DHA/100 moles of glycerol] determined by GC analysis. Conditions ((unless stated otherwise) glycerol (1.0 mmol), Cu(II) complex 19.3 (5.0 p.mol), r=25°C, solvent acetonitrile/water. 

You first need to convert grams NaOH to moles NaOH, because molarity relates moles of solute to volume of solution. Then, you convert moles NaOH to liters of solution, using the molarity as a conversion factor. Here, 0.150 M means that 1 L of solution contains 0.150 moles of solute, so the conversion factor is ... 

The chemical potentials of dilute solutions may be expressed in terms of molality (moles of solute per kilogram of solvent) or molarities Ck (moles of solute per liter of solution) instead of mole fractions X/t. In electrochemistry it is more common to use molality ntk. For dilute solutions, since Xk = (A jfc/A soivent)> we have the following conversion formulas for the different units... 

All of the solution concentration units introduced in this chapter are direct proportionalities. Percentage concentration by mass is a direct proportionality between mass of solute and mass of solution molarity, between moles of solute and liters of solution molality, between moles of solute and kilograms of solvent and normality, between equivalents of solute and liters of solution. These proportional relationships allow you to think of solution concentration units as conversion factors between the two units in the fraction. Do you know mass of solution and need mass of solute Use percentage concentration. Do you know volume of solution and need moles of solute Use molarity. Thinking about solution concentration units in this way allows you to become more skilled at solving quantitative problems. 

MOLAR AMOUNT, MOLE FRACTION, REACTION EXTENT, CONVERSION, AND CONCENTRATION... 

Its reaction kinetics, provided a conversion in a liquid and homogeneous mix, is elaborated when the stoichiometry and the relevant function of the reaction velocity is determined. Stoichiometry is the description of the minimum, integral, molar conversion of reacting moles (reactants) j to the produced moles (products or resultants) i in accordance with the scheme... 

In many situations, the actual molar amount of the enzyme is not known. However, its amount can be expressed in terms of the activity observed. The International Commission on Enzymes defines One International Unit of enzyme as the amount that catalyzes the formation of one micromole of product in one minute. (Because enzymes are very sensitive to factors such as pH, temperature, and ionic strength, the conditions of assay must be specified.) Another definition for units of enzyme activity is the katal. One katal is that amount of enzyme catalyzing the conversion of one mole of substrate to product in one second. Thus, one katal equals 6X10 international units. 

The Mole, Molar Mass, and Mole-Gram Conversions... 

Strategy (1) Start by calculating the number of moles of Fe2+. Then (2) use the coefficients of the balanced equation to find the number of moles of Mn04. Finally, (3), use molarity as a conversion factor to find the volume of KMn04 solution. 

Molarity (M) A concentration unit defined to be the number of moles of solute per liter of solution, 95q, 259 concentration unit conversion, 261-262 potassium chromate, 263 Mole A collection of6.0122 X 1023 items. The mass in grams of one mole of a substance is numerically equal to its formula mass, 55. See also Amount Mole fraction (X) A concentration unit defined as the number of moles of a component divided by the total number of moles, 116-117,261 Mole-gram conversions, 55-56,68-68q... 

Chromium trioxide (obtained from J. T. Baker Chemical Company) is stored in a vacuum desiccator over phosphorus pentoxide prior to use. Six-mole equivalents of oxidant is required for rapid, complete conversion to aldehyde. With less than the 6 1 molar ratio, a second, extremely slow oxidation step occurs (see reference 7). 

A chemical equation tells us the relations between the amounts (in moles) of each reactant and product. By using the molar masses as conversion factors, we can express these relations in terms of masses. 

Batch reactors give the lowest possible fraction unreacted and the highest possible conversion for most reactions. Batch reactors also give the best yields and selectivities. These terms refer to the desired product. The molar yield is the number of moles of a specified product that are made per mole... 

Molar mass can be thought of as a conversion factor between mass in grams and number of moles. These conversions are essential in chemistry, because chemists count amounts of substances in moles but routinely... 

Avogadro s number and molar mass make it possible to convert readily among the mass of a pure element, the number of moles, and the number of atoms in the sample. These conversions are represented schematically in the flowchart shown in Figure 2-22. 

Sometimes chemists have to analyze substances about which they know very little. A chemist may isolate an interesting molecule from a natural source, such as a plant or an insect. Under these conditions the chemical formula must be deduced from mass percentage data, without the help of an expected formula. A four-step procedure accomplishes this by using mass-mole conversions, the molar masses of the elements, and the fact that a chemical formula must contain integral numbers of atoms of each element. 

As with all calculations of chemical amounts, we must work with moles. Because grams are asked for, we must do a mole-mass conversion this requires the molar mass of the substance, which in turn requires that we know the chemical formula. 

We have information about molarity (mol/L) and density (g/mL) and are asked to find molality (mol/kg) and mole fraction (mol/mol). A good way to approach conversions from molarity to another measure is to choose a convenient volume for the solution, determine its mass and the mass of solute, and find the mass of water by difference. Then convert mass of water to kilograms and to moles to complete the calculations. 

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