All chemicals in the reaction A + 6 B ⇄ 2 C + 3 D are initially 8 M. When equilibrium is
reached, it is found that [B] = 10.4 M. What is the value of [C]eq?
From the balanced chemical equation, we can see that the stoichiometric ratio between B and C is 6:2, or 3:1. This means that for every 3 moles of B that react, 1 mole of C is produced.
Since [B]eq = 10.4 M, we can say that the number of moles of B present at equilibrium is equal to 10.4 M * the volume (in liters) of the solution.
The number of moles of C present at equilibrium is therefore equal to 1/3 of the number of moles of B present at equilibrium.
Since the initial concentration of B is 8 M, the initial number of moles of B is equal to 8 M * the volume (in liters) of the solution.
Therefore, the value of [C]eq is equal to (10.4 M * volume) / 3.