Molar mass of compounds

Osmosis is the flow of solvent through a semipermeable membrane into a solution the osmotic pressure is proportional to the molar concentration of the solute. Osmometry is used to determine the molar masses of compounds with large molecules, such as polymers reverse osmosis is used in water purification. 

Organic chemists once used freezing-point and boiling-point measurements to determine the molar masses of compounds that they had synthesized. When 0.30 g of a nonvolatile solute is dissolved in 30.0 g of CC14, the boiling point of the solution is 77.19°C. What is the molar mass of the compound ... 

Molar mass of compound = nx empirical mass of compound n = an integer (scale factor)... 

Molar mass of compound = n x Molar mass of empirical formula, where n = 1,2,3... 

A chemist wishes to prepare a compound called compound E. The molar mass of compound E is 100 g/mol. The synthesis requires four consecutive reactions, each with a yield of 60%. 

Percent Composition Total mass of element x 100% Molar mass of compound Kw Equilibrium Constant for Water... 

The mole is the SI unit for amount. The molar mass, or mass in grams of one mole of an element or compound, is numerically equal to the atomic mass of monatomic elements and the formula mass of compounds and diatomic elements. To find a monatomic element s molar mass, use the atomic mass, but instead of having units of amu, the molar mass will have units of g/mol. So, the molar mass of carbon is 12.01 g/mol, and the molar mass of iron is 55.85 g/mol. How to find the molar mass of compounds and diatomic elements is shown in the next section. 

Until now, when you needed to perform molar conversions, you were given the molar mass of compounds in a sample. Where does this molar mass of compounds come from You can determine the molar mass of compounds the same way that you find the molar mass of individual elements—by using the periodic table. 

Formulas are used to calculate molar masses of compounds. 

Sample Problem F Calculating Molar Mass of Compounds... 

Modify the Excel worksheet of Figure 3-15 to compute the molar mass of compounds containing (a) three elements and (b) five elements. 

Mass of a sample (g) = (moles of sample) x (molar mass of compound)... 

We can extend this idea of the molar mass of an element to determine the molar mass of compounds. By analogy, the molar mass of a compound is simply the sum of the atomic weight of each element in grams multiplied by the subscript on the element in the formula of the compound. For instance, one mole of methane molecules (CH ) contains one mole of carbon atoms (molar mass = 12.0 g) and 4 moles of hydrogen atoms (4 X 1.0 g/mol =... 

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