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Question
Transition elements form binary compounds with halogens. Which of the following elements will form \[\ce{MF3}\] type compounds?
(i) \[\ce{Cr}\]
(ii) \[\ce{Co}\]
(iii) \[\ce{Cu}\]
(iv) \[\ce{Ni}\]
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Solution
(i) \[\ce{Cr}\]
(ii) \[\ce{Co}\]
Explanation:
\[\ce{Cr}\] and \[\ce{Co}\] form \[\ce{MF3}\] type of compounds. The ability of fluorine to stabilize the highest oxidation state is due to higher lattice energy in \[\ce{CoF3}\] and higher bond enthalpy for the higher covalent compound like \[\ce{CrF6}\].
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