In a reaction A --> B, when C is added it reacts irreversibly with A. What can we say about C? A. C will make the reaction spontaneous. B. C is an intermediate. C. C will lower the rate of the reaction. D. C will increase the kinetic energy of molecules.
The answer is C. For C, it can react irreversibly with A. That means when adding C, the concentration of A will decrease. For reaction A-->B. if A decrease, then the reaction rate will decrease.