Find the number of molecules of an ideal gas in a volume of 1.000 cm3 at STP.
STP means standard temperature-273.15K and pressure
101.325 kPa.
Volume of ideal gas at STP= 22.4L
Number of molecule in 22.4L of ideal gas at STP=Avogadro number =6.022
Now we know that
1Litre=103cm3
22.4L=22.4103cm3
Number of molecule in 22.4103cm3 of ideal gas at STP=6.022
Therefore,
Number of molecules in 1cm3 of ideal gas at STP=
=
.