The equilibrium reaction is:
\[ \mathrm{PCl_5 \rightleftharpoons PCl_3 + Cl_2} \] Given: \[ K_c = 1.844 \] Volume of vessel = 1 L
Initial moles of $\mathrm{PCl_5}$ = 3.0
Since volume is 1 L, molarity equals number of moles.
Step 1: ICE table 
Step 2: Write equilibrium constant expression \[ K_c = \frac{[\mathrm{PCl_3}][\mathrm{Cl_2}]}{[\mathrm{PCl_5}]} \] \[ 1.844 = \frac{x^2}{3-x} \] Step 3: Solve the equation \[ 1.844(3-x) = x^2 \] \[ x^2 + 1.844x - 5.532 = 0 \] Solving using quadratic formula: \[ x = \frac{-1.844 + \sqrt{(1.844)^2 + 4(5.532)}}{2} \] \[ x \approx 1.74 \] Step 4: Moles of $\mathrm{PCl_5}$ at equilibrium \[ n_{\mathrm{PCl_5}} = 3.0 - x \] \[ = 3.0 - 1.74 = 1.26 \text{ mol} \] Step 5: Express in required format \[ 1.26 \text{ mol} = 1258 \times 10^{-3} \text{ mol (rounded)} \] \[ \boxed{1258} \]
What will be the equilibrium constant of the given reaction carried out in a \(5 \,L\) vessel and having equilibrium amounts of \(A_2\) and \(A\) as \(0.5\) mole and \(2 \times 10^{-6}\) mole respectively?
The reaction : \(A_2 \rightleftharpoons 2A\)

Cobalt chloride when dissolved in water forms pink colored complex $X$ which has octahedral geometry. This solution on treating with cone $HCl$ forms deep blue complex, $\underline{Y}$ which has a $\underline{Z}$ geometry $X, Y$ and $Z$, respectively, are
At \(-20^\circ \text{C}\) and 1 atm pressure, a cylinder is filled with an equal number of \(H_2\), \(I_2\), and \(HI\) molecules for the reaction:
\[H_2(g) + I_2(g) \rightleftharpoons 2HI(g)\] The \(K_P\) for the process is \(x \times 10^{-1}\).
(x = ___________)
Given: \(R = 0.082 \, \text{L atm K}^{-1} \text{mol}^{-1}\)
What will be the equilibrium constant of the given reaction carried out in a \(5 \,L\) vessel and having equilibrium amounts of \(A_2\) and \(A\) as \(0.5\) mole and \(2 \times 10^{-6}\) mole respectively?
The reaction : \(A_2 \rightleftharpoons 2A\)