Question

Calculate the number of molecules of oxygen gas that occupies a volume Of 22 ml at 273K and 3 atm pressure.

Answer 1

22400 ml. of oxygen at 273 K temperature and 3-atm pressure = 22400 $\times$3/1= 67200 ml at STP.

So 224 ml of oxygen at 273 K and 3-atm = 224 $\times$3= 672 ml at STP

The number of Oxygen molecules present in 22400 ml of gas at STP=N

(where N= Avagadro Number)

Therefore 224 ml of oxygen at 273K and 3-atm pressure will contain =N$\times$672/22400 $\times$ N molecules.

$=3/100\times 6.022\times {10}^{23}$

$=18.066\times {10}^{21}$ Molecules $=1.8066\times {10}^{22}$ molecules