Molar mass empirical formula

Name Empirical formula Molar mass (gftnol) RegisOj number (CAS). 

Nam Empirical formula Molar mass(g/nKil) Re soy munber (CAS). 

Empirical formula Molar mass Melting point Vapor pressure Solubility... 

Empirical formula Molar mass Boiling point Physical state/odor... 

Empirical formula Molar mass Melting point Physical state/odor Vapor pressure Water solubility Specific gravity Stability Other properties... 

Stoichiometry Empirical formula, molar mass (freezing-point depression), molar mass (vapor density)... 

The combustion of 3.795 mg of liquid B, which contains only C, H, and O, with excess oxygen gave 9.708 mg of CO2 and 3.969 mg of H2O. In a molar mass determination, 0.205 g of B vaporized at 1.00 atm and 200.0°C and occupied a volume of 89.8 mL. Derive the empirical formula, molar mass, and molecular formula of B and draw three plausible stmc-tures. 

Plan The molecular formula subscripts are whole-number multiples of the empirical formula subscripts. To find this whole number, we divide the given molar mass (90.08 g/moI) by the empirical formula mass, which we find from the sum of the elements molar masses. Then we multiply the whole number by each subscript in the empirical formula. Solution The empirical-formula molar mass is 30.03 g/mol. Finding the whole-number multiple ... 

An unknown compound contains only carbon, hydrogen, and oxygen. Combustion analysis of the compound gives mass percents of 31.57% C and 5.30% H. The molar mass is determined by measuring the freezing-point depression of an aqueous solution. A freezing point of —5.20°C is recorded for a solution made by dissolving 10.56 g of the compound in 25.0 g water. Determine the empirical formula, molar mass, and molecular formula of the compound. Assume that the compound is a nonelectrolyte. 

We also know that the molar mass is a whole-number multiple of tire empirical formula molar mass, the sum of the masses of all the atoms in tire empirical formula. 

Molar mass = Empirical formula molar mass x n... 

For a particular compound, the value of n in both cases is tire same. Therefore, we can find n by calculating the ratio of the molar mass to tire empirical formula molar mass. 

Empirical formula molar mass For fructose, the empirical formula molar mass is ... 

In the first step, use the molar mass (which is given) and the empirical formula molar mass (which you can calculate based on the empirical formula) to determine n (the integer by which you must multiply the empirical formula to get the molecular formula). 

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