Answer
See the answer below.
Work Step by Step
a) The $ln\ C\ vs\ t$ has a linear regression $r^2=0.991$ and the $1/C\ vs\ t$ has a linear regression $r^2=0.995$, so we can assume this is a second-order process.
b) For a second-order process, $1/C=kt+1/C_0$, and the regression is: $1/C=0.0583\times t+100.93$, so the rate constant is $k=0.0583\ L/mol.s$
