Answer:
mass of Clâ = 1.46 g
Explanation:
given data
mass of phosphorus trichloride  = 3.66 G
mas of chlorine gas = ?
efficiency = 83.7 %
balanced chemical equation
   2P + 3Clâ â 2PClâ
The mole ration of chlorine and phosphorus trichloride = 3 : 2
First we will find out number of moles of Clâ and PClâ
As we know that:
    number of moles = mass / molar mass
    number of moles of PClâ  =  3.66 g / 137.33 g.mol-
    number of moles of PClâ  = 0.027 mol
As the mole ratio of PClâ and Clâ = 2 : 3
   so number of moles of Clâ  = (0.027 Ă3) / 2
   number of moles of Clâ  = 0.041
Now we find the mass of Clâ
   mass of Clâ = moles Ă molar mass
  mass of Clâ = 0.041 mol Ă 35.5 g/mol
  mass of Clâ = 1.46 g