Observe the given graph. What will be the unit for the rate constant?

Answer & explanation
Correct answer: option 3

Plot of log\(\frac{[R]_0}{[R]}\) vs time for a first order reaction.
Unit of rate constant = (mol)1-n(L)n-1s-1 where n is the order of reaction.
For first order reaction, n = 1
Unit of rate constant = s-1