Question

The equilibrium constant at 298K for a reaction $A+B\rightleftharpoons C+D$ is 100. If the initial concentration of all the four species were 1 M each, then equilibrium concentration of D (in $mol{L}^{-1}$) will be.

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• A. 0.818
• B. 1.182
• C. 0.182
• D. 1.818

Answer 1

The correct option is D 1.818

$A+B\rightleftharpoons C+D1111:initially(1-x)(1-x)(1+x)(1+x):atequilibrium$

$Kc={\left(\frac{1+x}{1-x}\right)}^2$
$Kc={\left(\frac{1+x}{1-x}\right)}^2=100$

$\frac{1+x}{1-x}=10$

$x=\frac{9}{11}$

Conc. of $D=1+x=1+\frac{9}{11}=\frac{20}{11}=1.818$