Final answer:
Checking the statements concerning a chemical reaction at equilibrium, we conclude that the concentrations of reactants decrease, products increase until equilibrium is achieved, and the rate of the forward and reverse reactions are equal.
Step-by-step explanation:
Checking the statements for the given chemical reaction in equilibrium, we can determine which ones are accurate based on the principles of chemical equilibrium.
- a. The concentration of A at equilibrium will be less than one mole per liter. This is true because, in a closed system starting with one mole of A, some of A will convert to B as the system reaches equilibrium.
- b. The concentration of B at equilibrium will be zero. This is false. Since we originally start with one mole of A and zero moles of B, and the reaction will proceed to form some quantity of B at equilibrium, B cannot be zero.
- c. The reaction quotient Q will be greater than the equilibrium constant K. Whether this is true or false can vary depending on the specific values of Q and K. However, immediately after A is added and before reaching the new equilibrium, Q is likely to be greater than K, as the system has more reactants than at equilibrium and the reaction will proceed toward forming more products to achieve equilibrium.
- d. The rate of the forward reaction will be equal to the rate of the reverse reaction. This is true because at equilibrium, the rates of the forward and reverse reactions are equal, and the concentrations of reactants and products remain constant.
When additional A is added to the system, the initial increase in the concentration causes a shift in the equilibrium as per Le Chatelier's Principle, moving the reaction toward forming more B. An ICE table can be used to quantitatively analyze this shift, where 'I' stands for the initial concentrations, 'C' for the change in concentrations, and 'E' for the equilibrium concentrations post disturbance.
For the reaction A(aq) + 2B(aq) ⇒ 2C(aq), the equilibrium constant expression is given by Kc = [C]² / ([A][B]²). If Kc is very small (Kc = 5 x 10⁻⁴ in this example), we can presume that at equilibrium, there is only a small conversion of reactants to products.