Chemical Kinetics

At 298 K , for a first order resction $(A \rightarrow P)$ the following graph is obtained. The rate constant ( in s ${ }^{-1}$ ) and initial concentration ( in mol $\mathrm{L}^{-1}$ ) of ' $A$ ' are respectively $(Y$-axis $=\ln (a-x): X$-axis $=$ time in sec)