# If an ideal gas has a pressure of 7.05 atm, a temperature of 379 K, and has a volume of 54.75 L, how many moles of gas are in the sample?

Apr 8, 2017

by using ideal gas equation

#### Explanation:

ideal gas equation : $P \cdot V = n \cdot R \cdot T$
P : pressure
V : volume
n : moles of gas
R : universal gas constant
T : temperature

R has different values for in different units
R = 8.314 J/mol-k
R = 0.0821 L-atm/mol-k
and so on.
here we will use R = 0.0821 L-atm/mol-k
now substitute given values in ideal gas equation
$7.05 \cdot 54.75 = n \cdot 0.0821 \cdot 379$
n = 12.4 mol