A gaseous mixture contains 56 g of N2 , 44 g of CO2 and 16 g of CH4 . The total pressure of the mixture is 720 mm of Hg.

Number of moles of N₂ = mass (m)/ molar mass (M) 

= 56/28  

= 2 moles

Number of moles of CO₂ = 44/44  

 = 1 mole

Number of moles of CH₄ = 16/16  

= 1 mole

Total number of moles = 2 + 1 + 1

= 4 moles

Partial Pressure of CH₄ = mole fraction of CH4 x total pressure

= 1/4 x 720 

= 180 atm. 

Thus the partial pressure of Methane is 180 atm. 

Final Answer: The correct option is C: 180 atm