Question

$A\left(g\right)+3B\left(g\right)\rightleftharpoons 4C\left(g\right)$
Initial concentration of A is equal to that of B. The equilibrium concentration of A and C are equal. $K_c$ of the reaction will be:

• A. $0.08$
• B. $0.8$
• C. $8$
• D. $80$

Answer 1

The correct option is C $8$

$A\left(g\right)+3B\left(g\right)\rightleftharpoons 4C\left(g\right)$
$t=0aa0$
$t_{eq.}a-xa-3x4x$
Given that
$a-x=4x$
$\Rightarrow a=5x$
$K_c=\frac{[C{]}^4}{\left[A\right][B{]}^3}=\frac{[4x{]}^4}{\left[4x\right][2x{]}^3}=\frac{256}{32}=8$