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Chemical calculations molarity

The chemical formula of a compound contains essential information about its composition. The formula identifies which elements are present, and it states the number of atoms of each kind present in one unit of the compound. We need the chemical formula of a substance to calculate its molar mass. In fact, almost all chemical calculations require the correct chemical formula. How are chemical formulas determined in the first place ... [Pg.155]

For work in the laboratory, it s necessary to weigh reactants rather than just know numbers of moles. Thus, it s necessary to convert between numbers of moles and numbers of grams by using molar mass as the conversion factor. The molar mass of any substance is the amount in grams numerically equal to the substance s molecular or formula mass. Carrying out chemical calculations using these relationships is called stoichiometry. [Pg.106]

In a science laboratory, the most useful way of expressing the concentration of a solution is a ratio of moles of solute to liters of solution. This is called molarity and is abbreviated M. In a chemical change, it is useful to know the number of moles of solute that react. The formula for calculating molarity is... [Pg.95]

The new diffusion models are successful in the description they provide, and are particularly useful because they require only the chemical structure as an input, no experimental data being necessary. Molecular size is described by the use of the calculated molar refractivity. A new model for the temperature dependence of the viscosity of water was required and developed. [Pg.543]

In chemical calculations, use the Periodic Table in Appendix D to find the molar mass of any substance. [Pg.86]

Thermochemical experiments were performed to determine the standard molar enthalpy of formation of anthranil in the gaseous phase. A comparison of this value with that obtained from quantum-chemical calculations for 1,2-benzisoxazole showed that anthranil 1 is significantly less stable (A//°f= 180.8 2.1 kjmol ) than its isomer 2 (A//°f= 138.9 3.1 kJmoP ). This difference of about 42kJmol , even if significant, suggests that by thermochemical criteria, if aromatic character is ascribed to 1,2-benzisoxazole, a significant aromatic character must also be associated with anthranil <2004EJ03340>. [Pg.373]

The relative molecular mass that is determined by the mass spectrometer is numerically different from the chemical (average) molecular mass used to calculate molar concentrations or reaction stoichiometries. For the elements... [Pg.135]

The chemical structure representation in Apex-3D is based on the concept of a descriptor center that represents a part of the hypothetical biophore. Descriptor centers can be atoms, sets of atoms, pseudo-atoms, or substructures that participate in ligand-receptor interactions. The interaction is derived from electrostatic, hydrophobic, dispersion force, and charge-transfer information that comes from quantum-chemical calculations or from atomic conkibutions to hydrophobicity or molar refractivity. [Pg.253]

The term molar mass is used all the time in chemical calculations, so you need to know what it means. First, it is a mass, so it has units of mass, commonly the gram. Second, it concerns the mole (Avogadro s number). Whether you re dealing with elements or compounds, the molar... [Pg.110]

By definition, the atomic mass of the carbon-12 atom is exactly 12.00 amu. One mole of carbon-12 atoms has a mass of exactly 12.00 g, and that 12.00 g mass contains exactly 6.022 x 1023 carbon-12 atoms. This statement sets the benchmark for all chemical calculations involving the mole. One mole of any element is an amount of that element equal to its atomic mass in grams (its molar mass), and that mass contains 6.022 x 1023 atoms of that element. Using atomic masses, you can apply these relationships to the elements hydrogen and nitrogen. [Pg.111]

To design reactors, we have to calculate molar and energy balances considering that reactions can also take place under nonisothermal conditions. These balances contain always the generation term due to the chemical reaction, which is represented by the reaction rate. [Pg.293]

Molar mass is useful for chemical calculations because it provides a connection between a quantity that is easy to measure (mass) and one that is conceptually important (moles). Another readily measured quantity is volume. When we work with aqueous solutions, we often use volume in calculations rather than mass. It should not be surprising, therefore, that we would want to define quantities that will help us relate a volume measurement to the number of moles. [Pg.109]

Sample Target Phase Calculated Molar Ratio Measured Molar Ratio Starting Chemicals Hydrolysis Ratio SA, m2/g... [Pg.446]

You will calculate molar masses from chemical formulas (Section 7.4). [Pg.271]

To understand solution stoichiometry, you must first understand both fundamental stoichiometry concepts and solution concentrations. If you have difficulty solving solution stoichiometry problems, ask yourself if you thoroughly understand (a) writing chemical formulas from names, (b) calculating molar masses... [Pg.494]

When the concentration of a solution of a given retinoid or carotenoid is known, the best way to express the value is by using molar units, e.g. a plasma concentration of 2 pmol/1 is equivalent to 57.2 pg/dl. In such chemical calculations, molecular weights are used 286 g/mol for vitamin A and 537 g/mole for P-carotene. [Pg.31]

The standard state chosen for the calculation of controls its magnitude and even its sign. The standard state is established when the concentration scale is selected. For most solution kinetic work the molar concentration scale is used, so A values reported by different workers are usually comparable. Nevertheless, an important chemical question is implied Because the sign of AS may depend upon the concentration scale used for the evaluation of the rate constant, which concentration scale should be used when A is to serve as a mechanistic criterion The same question appears in studies of equilibria. The answer (if there is a single answer) is not known, though some analyses of the problem have been made. Further discussion of this issue is given in Section 6.1. [Pg.220]

Stoichiometry in Reactive Systems. The use of molar units is preferred in chemical process calculations since the stoichiometry of a chemical reaction is always interpreted in terms of the number of molecules or number of moles. A stoichiometric equation is a balanced representation that indicates the relative proportions in which the reactants and products partake in a given reaction. For example, the following stoichiometric equation represents the combustion of propane in oxygen ... [Pg.334]


See other pages where Chemical calculations molarity is mentioned: [Pg.115]    [Pg.115]    [Pg.1003]    [Pg.98]    [Pg.694]    [Pg.220]    [Pg.603]    [Pg.153]    [Pg.430]    [Pg.2834]    [Pg.488]    [Pg.274]    [Pg.410]    [Pg.320]    [Pg.142]    [Pg.169]    [Pg.102]    [Pg.266]    [Pg.189]    [Pg.374]    [Pg.196]    [Pg.82]    [Pg.730]    [Pg.203]    [Pg.4]    [Pg.117]    [Pg.111]    [Pg.724]    [Pg.249]    [Pg.561]    [Pg.272]    [Pg.62]    [Pg.137]    [Pg.140]   
See also in sourсe #XX -- [ Pg.109 , Pg.110 ]




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