Question

# Copper forms two chlorides CuCl and $CuCl_{ 2 }$.(a) Identify the copper ions in these compounds?(b) What is the valency of copper in each of these compounds?(c) By writing the subshell electronic configuration of copper, find out the subshells from which the electrons are lost to form these ions.(d) Write the period and group to which copper belongs.(Hint: Atomic number of Copper=29)

The total charge on $CuCl_{ 2 }$ is 0. And the general valency of copper is -1. The number of chlorine atoms is 2. So the charge of copper will be +2. It is the higher oxidation state of copper. The compound is called cupric chloride. Cupric ions form a precipitate when reacted with hydrogen sulfide. It forms a blue color complex in the presence of aqueous ammonia.
Copper has 29 electrons in its neutral form. It has d subshell electrons. Electronic configuration of copper is $1s^{ 2 }2s^{ 2 }2p^{ 6 }3s^{ 2 }3p^{ 6 }3d^{ 10 }4s^{ 1 }$.
Configuration $Cu^{ + }$ ion is $1s^{ 2 }2s^{ 2 }2p^{ 6 }3s^{ 2 }3p^{ 6 }3d^{ 10 }$. Electrons are lost from the 4s subshell.
Configuration $Cu^{ +2 }$ ion is $1s^{ 2 }2s^{ 2 }2p^{ 6 }3s^{ 2 }3p^{ 6 }3d^{ 9 }$. Electrons are lost from the 3d subshell.