Any suggestions how to solve this?
Calculate $n(\ce{FeSO4})$ with $M(\ce{FeSO4})\approx 136\:\mathrm{g/mol}$


   $n(\ce{FeSO4})\approx0.08\:\mathrm{mol}$


Calculate $n(\ce{H2O})$


   $n(\ce{H2O})\approx0.5\:\mathrm{mol}$


Set them into relation $n(\ce{FeSO4}):n(\ce{H2O})= 1:x$


   $x\approx 6$