Question

Which of the following is a characteristic of a reversible reaction? (1) No. of moles of reactants and products are equal (2) It can never proceed to completion (3) It can be influenced by a catalyst (4) All of these

Answer 1

In a reaction at dynamic equilibrium:

(i) The amount of reactants and products are constant, but not necessarily equal, and
(ii) The activation energy may be lowered via a catalyst's provision of an alternative pathway, improving the reaction rate,

`K_(eq) = (k_f)/(k_r)`

Hence, (3) is likely the answer, I know (1) and (4) aren't. And most reactions aren't irreversible, unless they are in a closed system, which I guess eliminates (2).