A sample of nitrogen gas has 2.68 x 10^22 molecules measured at 87.0 degrees C and 0.620 atm. What is it's volume?

2)
n / V = P / RT = (97.2 kPa) / ((8.3144621 L kPa/K mol) x (50.0 + 273.15) K) = 0.036177 mol/L

(3.03 g/L) / (0.036177 mol/L) = 83.75 g/mol

The gas with a molar mass like that is krypton, Kr.

[Now you see the trouble with multiple answers per question: Who gets Best Answer if we're both correct?]

Gas law questions....

The question is worded a bit strangely. A sample of N2 will have the same number of molecules regardless of the temperature or pressure.

PV = nRT ............. ideal gas equation
V = nRT / P .......... solve for V
V = (2.68x10^22 molecules x (1 mol / 6.022x10^23 molecules) x 0.08206 Latm/molK x 360K / 0.630 atm
V = 2.09L .............. to three significant digits

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PV = nRT .................... ideal gas equation
PV = mRT / M ............. n = m / M.... m=mass, M=molar mass
P = m/V (RT/M) ........... rearrange
P = DRT/M .................. D = m/V
M = DRT/P .................. solve for M (the molar mass)
M = 3.03g/L x 8.314 LkPa/molK x 323K / 97.2 kPa
M = 83.7 g/mol

The name of the gas is "unknown." There are no doubt lots of gases with molar masses at or near 83.7 g/mol, but if its an element, then go with Kr.

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Use this equation: PV = mRT / M. Solve for volume, then convert to milliliters.

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Use Avogadro's constant (6.022x10^23 mol⁻¹) to convert to moles of hydrogen. Then use the ideal gas equation (PV = nRT) to solve for pressure.

A sample of nitrogen gas has 2.68 x 10^22 molecules measured at 87.0 degrees C and 0.620 atm. What is it's volume?
--- (2.68 x 10^22 / 6.022 x 10^23)(0.0821)(360)/0.620 <<< use a calculator .. answer will be liters