Which correctly describe a reversible reaction reaching equilibrium in a closed system? Select two that apply. Over time, the rate of the reverse reaction becomes greater than the forward reaction. Over time, the rate of the forward reaction becomes zero. Initially, the concentration of products is low, so the rate of the reverse reaction is also low. Initially, the concentration of reactants is low, so the rate of the forward reaction is also low. Over time, the rates of the forward and reverse reactions equalize. Equal amounts of gases A and B are placed in a closed reactor. A and B react to combine into AB in the following equilibrium reaction: A + B ⇌ AB Which are true about this system? Select two that apply. A closed system does not allow for the transfer of energy in and out, so energy is conserved in the system. The total mass in the reactor gradually becomes zero because products are removed from closed systems. A closed system allows for the transfer of energy in and out, so energy is not conserved in this system. The total mass in the reactor gradually becomes zero because mass is consumed in closed systems. The total mass in the reactor remains the same because products are removed from closed systems. The total mass in the reactor remains the same because mass is conserved in closed systems. Read the reaction and the statement. 2X(g) + Y2(g) ⇌2XY(s) The equilibrium constant for the chemical reaction is found to be 20 at 150 K. If the concentration of X is 4.0 × 10-2 M, what is the concentration of the Y2 gas?