Question

What is the molar mass of a single poly(vinylidene chloride) molecule containing 3.123 x 10^4 repeating units?

a. 1.952 x 10^6 g/mol
b. 1.22 x 10^6 g/mol
c. 2.844 x 10^6 g/mol
d. 5.123 x 10^-7 g/mol
e. 3.5173 x 10^9 g/mol

Answer 1

The molar mass of a single poly(vinylidene chloride) molecule with 3.123 x 10^4 repeating units is closest to 2.844 x 10^6 g/mol, which is option c.

Step-by-step explanation:

The question is asking for the molar mass of a single poly(vinylidene chloride) molecule that contains 3.123 x 104 repeating units. To calculate the molar mass of this molecule, we need the empirical formula and molar mass of a single repeating unit of poly(vinylidene chloride). For Saran, which is poly(vinylidene chloride), the empirical formula is calculated based on its composition: 24.8% Carbon (C), 2.0% Hydrogen (H), and 73.1% Chlorine (Cl).

Using the atomic masses from the periodic table: C (12.01 g/mol), H (1.01 g/mol), Cl (35.45 g/mol), and calculating for one repeating unit (C2H2Cl2), we find the molar mass of a single unit to be (2*12.01) + (2*1.01) + (2*35.45) = 96.94 g/mol. To find the molar mass of the entire molecule, we multiply this by the number of units: 96.94 g/mol * 3.123 x 104 = 3.026 x 106 g/mol, which is closest to option c, 2.844 x 106 g/mol.