Posted by Louis on .
Helium gas is added to a 2.00 L container at 23 degrees Celsius containing Neon and Argon with a pressure of 725.3 mm Hg, what is the mass of Nitrogen added if the pressure is increased by 50%.

Chemistry 
DrBob222,
Use PV = nRT and solve for n with the original mixture of Ne and Ar. Then use PV = nRT with P increased by 50% and solve for n.
n2  n1 = moles N2 added.
n = grams/molar mass. Solve for grams.