Question

What is the volume of 5.6 moles of nitrogen gas at STP?

Answer 1

There are two ways to calculate this if we assume STP of 1 atm and 273 K for the pressure and temperature.

We can use the Ideal Gas Law equations PV = nRT
P = 1 atm
V = ???
n = 5.60 moles
R = 0.0821 `(atmL)/(molK)`
T = 273 K

`PV=nRT` can be `V =(nRT)/P`

`V = (((5.60 mol)(0.0821(atmL)/(molK))(273K))/(1 atm))`

#V = 125.51 L

The second method is to us Avogadro's Volume at STP `22.4 L = 1mol`

`5.60 mol x (22.4 L)/(1 mol) = 125.44 L`

In both cases the significant digit count is three figures which means the acceptable solution is `125 L`.

I hope this was helpful.
SMARTERTEACHER