Question

calculate the number of molecules of oxygen gas that occupies a volume of 224 ml at 273 K and 3 atm pressure.

Answer 1

From the Question, 
Volume of the Gas(V)  = 224 mL.
= 0.224 liter. 
Temperature of the Gas(T)  = 273 K.
Pressure of the Gas(T) = 2 atm 

Now, Using the Formula,

PV = nRT
where, R = Gas Constant = 0.082 L-atm mol⁻¹ K⁻¹
 and n = number of moles. 

∴ 2 × 0.224 = n × 0.082 × 273
∴ 0.448 = 22.386 × n
⇒ n = 0.448/22.386
⇒ n =  0.02 moles.


Now,  
Using the Formula,
 No. of molecules = No. of moles × 6.022 × 10²³
 = 0.02 × 6.022 × 10²³
 = 0.121 × 10²³


Thus, the number of the molecules of the Oxygen gas is 0.121 × 10²³ molecules.


I Hope it will helps you. 

Answer 2

Answer:

1.807*10^22

Explanation:

Answer is attached... Hope it is correct