The volume of 0.20 moles of helium at STP is 4.5 liters.
Explanation:
Given:
Number of moles = 0.20 moles
To Find:
The volume of Helium at STP =?
Solution:
According to ideal gas law
PV = nRT
where
P is pressure,
V is volume,
n is the number of moles
R is the gas constant, and
T is temperature in Kelvin.
The question already gives us the values for p and T
,because helium is at STP. This means that temperature is 273.15 K and pressure is 1 atm
.
We also already know the gas constant. In our case, we'll use the value of
0.08206 L atm/K mol since these units fit the units of our given values the best
On substituting these values we get
[tex]1 atm \times V = 0.20 moles \times 0.08206 L atm/K mol[/tex]
[tex]V = \frac{0.20 moles \times 0.08206 L atm/K mol }{ 1 atm}[/tex]
[tex]V = \frac{4.482}{1}[/tex]
V = 4.5 Liters
