5.8 What will be the pressure of the gaseous mixture when 0.5 L of H2 at 0.8 bar and 2.0 L of dioxygen at 0.7 bar are introduced in a 1L vessel at 27°C?

 

NEETprep Answer: 
                        

Let the partial pressure of H2 in the vessel be pH2.

Now,

p1 = 0.8 bar                    p2 = pH2
V1 = 0.5 L                      V2 = 1 L

It is known that,

p1V1  = p2V2
 p2 = p1V1V2
 pH2 = 0.8×0.51
              = 0.4 bar

Now, let the partial pressure of O2 in the vessel be pO2.

Now,

p1 0.7 bar       p2 = pO2 = ?
V1 = 2.0 L    V2 = 1 L

      p1V1 = p2V2
    p2 = p1V1V2
 pO2 = 0.7×201
               = 0.4 bar

Total pressure of the gas mixture in the vessel can be obtained as:

ptotal = pH2 + pO2
         = 0.4 + 1.4
        = 1.8 bar

Hence, the total pressure of the gaseous mixture in the vessel is 1.8 bar.