Question

In the reaction $X\left(g\right)+Y\left(g\right)\rightleftharpoons 2Z\left(g\right),2$ 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 $0.2M$, then $K$ for the given reaction is:

• A. $1.60$
• B. $\frac{80}{3}$
• C. $\frac{16}{3}$
• D. $Noneofthese$

Answer 1

Answer: (A)

$1.60$

$X\left(g\right)+Y\left(g\right)\rightleftharpoons 2Z\left(g\right)$

initially $\frac{1}{10}$ $\frac{1}{10}$ $\frac{1}{10}$

finally $\frac{1}{10}-\alpha$ $\frac{1}{10}-\alpha$ $\frac{1}{10}+2\alpha$

According to question,

$\frac{1}{10}+2\alpha =0.2$

$2\alpha =0.1$

$\alpha =0.5$

$\left[X\right]=0.1-0.05=00.5$

$\left[Y\right]=0.1-0.05=0.05$

$\left[Z\right]=0.1+0.1=0.2$

$K=\frac{[Z{]}^2}{\left[X\right]\left[Y\right]}=\frac{(0.2{)}^2}{\left(0.05\right)\left(0.05\right)}=\frac{0.04}{0.0025}=1.60$