Question

What is the number of moles in 40.0 L of He gas at STP?

Answer 1

Answer: There are 1.78 moles in 40.0 L of He gas at STP

Step-by-step explanation:

According to ideal gas equation:

`PV=nRT`

P = pressure of gas = 1 atm (STP)

V = Volume of gas = 40.0 L

n = number of moles = ?

R = gas constant =
`0.0821Latm/Kmol`

T =temperature =
`273K` (STP)

`n=(PV)/(RT)`

`n=(1atm* 40.0L)/(0.0821Latm/K mol* 273K)=1.78moles`

Thus there are 1.78 moles in 40.0 L of He gas at STP