ideal gas law calculating moles

Question

A 5.46 gram sample of nitrogen gas has a volume of 868 milliliters at a pressure of 3.49 atm. The temperature of the N₂ gas sample is ________ °C.

It is desired to inflate a baggie with a volume of 868 milliliters by filling it with nitrogen gas at a pressure of 0.739 atm and a temperature of 301 K. How many grams of N₂ gas are needed?________  g

Answer 1

PV = nRT

P = 3.49 atm

V = 868 ml = 0.868 L

n = 5.46 g x 1 mol N2/28 g = 0.195 moles

R = 0.0821 Latm/Kmol

T = ?

Plug values into ideal gas law equation and solve for T. Subtract 273 to get ºC

P = 0.739 atm

V = 0.868 L

n =?

R = 0.0821 Latm/Kmol

T = 301K

n = PV/RT = (0.739)(0.868)/(0.0821)(301) = 0.02596 moles N₂

0.02596 moles N₂ x 28 g/mole = 0.727 g N₂