Question

8.2L of an ideal gas weights 9gm at 300K and 1 atm. pressure. The molar mass of the gas is- a. 9 b. 27 c. 54 d. 81

Answer 1

First calculate the mole of gas as follows:

 

n  = PV/ RT

= 1.00 atm   * 8.2 L/ 0.08206 atm .L/ mole K * 300 K

= 0.333 moles

Molar mass = amount in g / number of moles

= 9 g/ 0.333 moles

= 27 g/ mole

Thus the correct answer is b.27