Question

A 2.95 g sample of an unknown chlorofluorocarbon (an organic compound containing chlorine and fluorine) is decomposed and produces 581 mL of chlorine gas at a pressure of 752 mmHg and a temperature of 298 K. What is the percent by mass of chlorine in the chlorofluorocarbon?

Answer 1

mass percent of chlorine is 56.5%

Step-by-step explanation:

Given data:

Volume V = 581 mL = 0.581 L

Pressure P = 752 mm of Hg = 752/760 = 0.9894 atm

Temperature T = 298 K

Molar gas constant R = 0.08206 atm.L/mol.K

from Ideal gas equation we have following relation

PV = nRT solving for n

`n = (PV)/(RT)`

`n = (0.9894 * 0.581)/(0.08206 * 298)`

n = 0.0235 mole

mas of
`Cl_2` = moles × molar mass of
`Cl_2`

`= 0.0235 * 70.906 = 1.66 g`

Mass percent of chlorine
`=  (mass\ of\ Cl)/(mass\ of\ sample)`

`=(1.66)/(2.95) = 0.565 = 56.5 %`