Question

A sealed 5.00L flask contains an unknown gas at 1.05 atm and 296 K. How many moles of the unknown gas are in the flask?

Answer 1

Moles of the unknown gas in the flask : 0.216

Further explanation

The gas equation can be written  

$\large {\boxed {\bold {PV = nRT}}}$

where  

P = pressure, atm  

V = volume, liter  

n = number of moles  

R = gas constant = 0.08206 L.atm / mol K  

T = temperature, Kelvin  

V=5 L

P = 1.05 atm

T = 296 K

$\tt n=\dfrac{PV}{RT}\\\\n=\dfrac{1.05\times 5}{0.082\times 296}\\\\n=0.216$