The rate constant is constant at all temperatures.
Consider the following reaction at equilibrium, 2NH3 (g) ⇌ N2 (g) + 3H2 (g).
If the concentration of hydrogen gas is increased,
a. then the equilibrium will shift to the right.
b. then the forward and reverse reaction will speed up.
c. nothing happens.
d. then the equilibrium will shift to the left.