In which one of the following equilibria, 

K_{p}\neq K_{c}?

  • Option 1)

    2C(s)+O_{2}(g)\rightleftharpoons 2CO(g)

     

     

     

     

  • Option 2)

    2HI(g)\rightleftharpoons H_{2}(g)+I_{2}(g)

  • Option 3)

    NO_{2}(g)+SO_{2}(g)\rightleftharpoons NO(g)+SO_{3}(g)

  • Option 4)

    2NO(g)\rightleftharpoons N_{2}(g)+O_{2}(g)

Answers (1)

 

Equilibrium constant in gaseous system -

For equilibrium involving gases, it is usually more convenient to express the equilibrium constant in terms of partial pressure. 

- wherein

The ideal gas equation is written as 

PV=nRT

 

 

 

 

Relation between Kp and Kc -

K_{p}=K_{c}(RT)^{\bigtriangleup n}

while calculating the value of Kp , pressure should be expressed in bar.

1\:bar=10^{5}pa

- wherein

\bigtriangleup n = (number of moles of gaseous products) - (number of moles gaseous reaction)

 

 

 

K_{p}=K_{c}(RT)^{\Delta n}            IF \Delta n=0            K_{p}=K_{c}

                                                IF \Delta n\neq 0               K_{p}\neq K_{c}

\Delta n= changes in the number of moles of gas 

= (total moles of gas in product side) - (Total moles of g on reactant size, check again option )

2C(s)+O_{2}(g)\rightleftharpoons 2(Olg))    

solid phase

\Delta n=2-1=1\rightarrow K_{p}\neq K_{c}


Option 1)

2C(s)+O_{2}(g)\rightleftharpoons 2CO(g)

 

 

 

 

Option 2)

2HI(g)\rightleftharpoons H_{2}(g)+I_{2}(g)

Option 3)

NO_{2}(g)+SO_{2}(g)\rightleftharpoons NO(g)+SO_{3}(g)

Option 4)

2NO(g)\rightleftharpoons N_{2}(g)+O_{2}(g)

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