Which of the following for a chemical reaction can never be a fraction?

For a second-order reaction where both reactants have the same initial concentration,it takes $500 \ s$ for the reaction to be $20\%$ complete. How many seconds will it take for the reaction to be $80\%$ complete (in $s$)?

Which among the following is a false statement?

If the order of a reaction is $x$,then the unit of its rate constant is:

Identify the rate law expression for the reaction $2 NO_{(g)} + Cl_{2(g)} \rightarrow 2 NOCl_{(g)}$ if the reaction is second order in $NO$ and first order in $Cl_2$.

Rate law for the reaction $aA + bB \rightarrow cC + dD$ is $r = k[A][B]$. Which of the following conditions does $NOT$ affect the rate of reaction?