physics help?

Question

A sample of gas at 20 degrees Celsius has a volume of 0.6L at a pressure of 0.8atm. find the number of moles and the number of molecules?

Answer 1

use the formula P1V1/T1=P2V2/T2
at STP vol of 1 mol is 22.4 litre
STP is 1 atm pressure 0*celsius temp

Answer 2

Assuming your gas acts like an ideal gas, it follows Boyle's Law,

PV=nRT

P=pressure in atm
V=Volume in Liters
n=number of moles of gas
R=gas constant = 0.0821 L atm/K mol
T= temperature in Kelvins

So converting 20 C gives us 293.15K

Number of moles (n) = PV/RT = 0.8 atm X 0.6 L / 0.0821 X 293.15K
= 1.994 X 10^-2 mols, or 1.20 X 10^ 22 molecules of gas.