The addition of a catalyst during a chemical reaction alters which of the following quantities?

The rate constant of the reaction A $$ \to $$ B is 0.6 $$ \times $$ 10^$$-$$3 mol L^$$-$$1 s^$$-$$1. If the concentration of A is 5 M, then concentration of B after 20 minutes is

When initial concentration of a reactant is doubled in a reaction, its half-life period is not affected. The order of the reaction is

The activation energy of a reaction can be determined from the slope of which of the following graphs?