Saved Bookmarks
| 1. |
At some temperature and under a pressure of 4 atm, PCl_(5) is 10% dissociated . Calculate the pressure at which PCl_(5) will be 20% dissociated , temperature remaining same. |
|
Answer» Solution :`{:(,PCl_(5) ,hArr,PCl_(3),+,Cl_(2)), (" Atm eqm. " ,1-0*1=0*9"mole",,0*1 "mole",,0*1"mole"):}` Total no. of MOLES ` = 0*9+ 0*1 + 0*1= 1 * 1"mole " ` ` p_(PCl_(5))= (0*9)/(1 *1) xx 4"atm " , p_(PCl_(3))= (0*1)/(1*1)xx 4 " atm " , p_(Cl_(2)) = (0*1)/(1.1) xx 4 " atm " ` ` :. K_(p) = (p_(PCl_(3))xx p_(Cl_(2)))/ (p_(PCl_(5))) = ((0*4)/(1*1) xx (0*4)/(1*1))/((0*9 xx 4)/(1*1) )=0*0404 ` 2nd caseWhen `PCl_(5)` is20% dissociated . Suppose total pressure= P atm . Then `{: (,PCl_(5),hArr,PCl_(3),+,Cl_(2)),("INTIAL " ,1 "mole",,,,),("At equilibrium " ,1-0*2=0*8,,0*2,,0*2 "mole"),(,,,,," Total no. of moles"= 0*8 + 0*2 + 0*2 = 1*2 "moles"):}` ` p_(PCl_(5)) = (0*8)/(1*2) xxP atm , p_(PCl_(3)) = (0*2)/(1*2) xx P atm , p_(Cl_(2))= (0*2)/(1*2) xx P atm ` ` K_(p)= ((0*2 P)/(1*2) xx(0*2)/(1*2))/(( 0*8P)/(1*2))= (0*2)/(1*2) xx (0*2)/(0*8) P = 0*0404("calculated above")` which GIVES `P= 0* 97 ` atm |
|