Answer to Question #105600 in Physical Chemistry for Danish

Question

What is reaction quotient amd how it is helpful in determining the direction of a given reaction

Answer 1

Consider a reaction

$aA+bB\to cC+dD$

Reaction quotient$(Q)$ $=\frac{[C]^c[D]^d}{[A]^a[B]^b}$

Where $[D]$ represent the concentration of $D$ at any moment and $d$ is its stochiometric cofficient .

The $Q$ value can be compared to the equilibrium constant, $K$ ,to determine the direction of reaction that is taking place.

If $Q<K,$ reaction will move forward toward product side to attain equilibrium.

If $Q=K,$ reaction is in equilibrium.

If $Q>K,$ reaction will move backward towards reactant side to attain equilibrium.