Question

In the reaction $X\left(g\right)+Y\left(g\right)\leftrightharpoons 2Z\left(g\right)$, 2 mole of X, 1 mole of Y and 1 mole of Z are placed in a 10 litre vessel and allowed to reach equilibrium. If final concentration of Z is 0.2 M, then $K_c$ for the given reaction is :

• A. $1.60$
• B. $\frac{80}{3}$
• C. $\frac{16}{3}$
• D. none of these

Answer 1

Answer: (C)

$\frac{16}{3}$

$X+Y\rightleftharpoons 2Z$

$n=2$ $1$ $1$ $t=0$

$2-x$ $1-x$ $1+2x$ $t_{equilibrium}$

given $1+2x=0.2$

$x=0.5$

$K_C=\frac{{\left[z\right]}^2}{\left[x\right]\left[y\right]}=\frac{{[1+2x]}^2}{[2-x][1-x]}=\frac{{\left(2\right)}^2}{\left(1.5\right)\left(0.5\right)}=\frac{16}{3}$