A reactant breaks down on a catalyst surface by a zero order reaction. At a concentration of $0.22\ \text{mol/L}$ the rate is $3.0 \times 10^{-3}\ \text{mol L}^{-1}\,\text{s}^{-1}$. How long does the concentration take to fall from $0.52\ \text{mol/L}$ to $0.34\ \text{mol/L}$?