Question

At a certain temperature, $2$ moles of $CO$ and $4$ moles of $Cl_2$ gases were reacted to form $COCl_2$ in a $10\, L$ vessel. At equilibrium if one mole of $CO$ is present then equilibrium constant for the reaction is

• A. 4
• B. 3.3
• C. 1
• D. 2.5
• E. 4.5

Answer 1

Answer: (B)

At equilibrium one mole of $CO$ is present

Therefore, $2-x=1$ (given)

$x=1$

On substituting the value of $x$, we get

1 mole of $CO =\frac{1}{10} ;$ conc. of 1 mole of $Cl _{2}=\frac{3}{10}$

conc. of 1 mole of $COCl _{2}=\frac{1}{10}$

Using these value, in equilibrium constant reaction.

$k_{C}=\frac{\left[ COCl _{2}\right]}{[ CO ]\left[ Cl _{2}\right]}=\frac{[ 1 / 10]}{\left[\frac{1}{10}\right]\left[\frac{3}{10}\right]}=\frac{10 \times 10}{10 \times 3}=3.3$