What is the concentration of A after 17.7 minutes for the reaction A → Products when the initial concentration of A is 0.750 M? (k = 0.0451 M⁻¹min⁻¹)

Answer 1

From the units of k (M-1min-1) we can tell that this is a 2nd order reaction.

See my answer to your previous question which was also 2nd order. In that question we solved for t. Here we solve for [A] since we know [A]_o and k and t.