JEE Main & Advanced
Chemistry
Equilibrium / साम्यावस्था
Question Bank
Kp and Kc Relationship and Characteristics of K
question_answer
\[{{A}_{(g)}}+3{{B}_{(g)}}\] ⇌\[4{{C}_{(g)}}\]. Starting concentration of A is equal to B, equilibrium concentration of A and C are same. \[{{K}_{c}}=\] [Kerala CET 2005]
A) 0.08
B) 0.8
C) 8
D) 80
E) 1/8
Correct Answer:
C
Solution :
A
+
3B
⇌
4C
a
b
0
(a ? x)
(b ? 3x)
4x
\[{{K}_{C}}=\frac{{{[C]}^{4}}}{[A]{{[B]}^{3}}}=\frac{4x.4x.4x.4x}{(a-x)(b-3x)}\] Given \[a=b,\,a-x=4x\Rightarrow a=5x=b\] \[{{K}_{C}}=\frac{4x.4x.4x.4x}{(5x-x)(5x-3x)}=\frac{4x.4x.4x.4x}{4x.2x.2x.2x}=8\].