Which of the following statements is not correct?
(i) Copper liberates hydrogen from acids.
(ii) In its higher oxidation states, manganese forms stable compounds with
oxygen and fluorine.
(iii) Mn3+ and Co3+ are oxidising agents in aqueous solution.
(iv) Ti2+ and Cr2+ are reducing agents in aqueous solution.
Option (i) Copper liberates hydrogen from acids is the answer.