Q 1 :    

For the given reaction, choose the correct expression of KC from the following:

Fe(aq)3++SCN(aq)-(FeSCN)(aq)2+                      [2024]

  • KC=[FeSCN2+]2[Fe3+][SCN-]

     

  • KC=[FeSCN2+][Fe3+]2[SCN-]2

     

  • KC=[Fe3+][SCN-][FeSCN2+]

     

  • KC=[FeSCN2+][Fe3+][SCN-]

     

(D)          Fe3+(aq)+SCN-(aq)(FeSCN)2+(aq)  

               Kc=[FeSCN2+][Fe3+][SCN-]

 



Q 2 :    

The equilibrium constant for the reaction SO3(g)SO2(g)+12O2(g) is KC=4.9×10-2. The value of KC for the reaction given below is

 

2SO2(g)+O2(g)2SO3(g) is :                        [2024]

  • 4.9

     

  • 49

     

  • 41.6

     

  • 416

     

(D)           SO3(g)SO2(g)+12O2(g),Kc=4.9×10-2 - I

                Reverse the above equation. On reversing a chemical equation, equilibrium constant gets inversed.

                 SO2(g)+12O2(g)SO3(g),Kc1=14.9×10-2 - II

                Multiply II by 2. On multiplying an equation by n, equilibrium constant gets raised by a power n.

                 2SO2(g)+O2(g)2SO3(g),Kc11=(14.9×10-2)2=416.49

 



Q 3 :    

At –20°C and 1 atm pressure, a cylinder is filled with equal number of H2I2 and HI molecules for the reaction H2(g)+I2(g)2HI(g), the Kp for the process is x×10-1x= _______ . [Given : R = 0.082 L atm K-1 mol-1]                      [2024]

  • 1

     

  • 2

     

  • 10

     

  • 0.01

     

(C)          nHI=nH2=nI2=x

                H2(g)+I2(g)2HI(g)

                Kp=Kc=[HI]2[H2][I2]=(nHI/V)2(nH2/V)(nI2/V)=(nHI)2nH2×nI2=(x)2x×x=10×10-1



Q 4 :    

The ratio KPKC for the reaction:

 

CO(g)+12O2(g)CO2(g) is :                       [2024]

  • RT

     

  • (RT)1/2

     

  • 1RT

     

  • 1

     

(C)              CO(g)+12O2(g)CO2(g)

                    Δng=Gaseous mol of product-gaseous mol of reactant

                              =1-(1+0.5)=-0.5

                     Kp=Kc(RT)Δng

                     KpKc=(RT)-0.5=1RT

 



Q 5 :    

For the given hypothetical reactions, the equilibrium constants are as follows:

 

XY; K1=1.0

 

YZ;K2=2.0

 

ZW;K3=4.0

 

The equilibrium constant for the reaction XW is                                        [2024]

  • 12.0

     

  • 6.0

     

  • 8.0

     

  • 7.0

     

(C)          On adding reactions, equilibrium constants are multiplied

                XY,K1=[Y][X]

                YZ,K2=[Z][Y]

                ZW,K3=[W][Z]

            ___________________

            Adding all three:

           XW,K=[W][X]=[W][Z][Y][Z][Y][X]=K1K2K3=1×2×4=8

 



Q 6 :    

For the reaction  N2O4(g)2NO2(g), Kp=0.492 atm at 300 K. Kc for the reaction at same temperature is _______ ×10-2. (Given: R = 0.082 L atm mol-1 K-1)                     [2024]



(2)  

N2O4(g)2NO2(g)

Δng= gaseous moles of products - gaseous moles of reactants

         =2-1=1

Kp=Kc(RT)Δng

0.492atm=Kc×(0.082atm L mol-1K-1×300K)1

Kc=0.4920.082×300mol L-1

      =0.02mol L-1=2×10-2mol L-1

 



Q 7 :    

The following concentrations were observed at 500 K for the formation of NH3 from N2 and H2. At equilibrium; [N2]=2×10-2M,[H2]=3×10-2Mand[NH3]=1.5×10-2M. Equilibrium constant for the reaction is _____________ .          [2024]



(417)

N2(g)+3H2(g)2NH3(g)

Kc=[NH3]2[N2][H2]3=(1.5×10-2)2[2×10-2][3×10-2]3=417