$\begin{array}{1 1} \text{(1) Iron corrodes in oxygen-free water. } \\ \text{(2) Iron corrodes more rapidly in salt water because its electrochemical potential is higher.} \\ \text{(3) Corrosion of iron can be minimized by forming a contact with another metal with a higher reduction potential. } \\ \text{(4) Corrosion of iron can be minimized by forming an impermeable barrier at its surface.}\end{array} $
