Question

# The valency of Cu in cuprous chloride (${ Cu }_{ 2 }{ Cl }_{ 2 }$) is 1.A.TrueB.False

Hint:To find the valency of copper first you need to write the electronic configuration and don’t confuse yourself with the molecular formula given, you can write it as CuCl.

- ${ Cu }_{ 2 }{ Cl }_{ 2 }$ is the dimeric formula of CuCl.
So, solving the valency of Cu in CuCl will be a lot easier to understand for us.
-Now, Copper (Cu) belongs to the 4th period and 11th group in the periodic table.
Electronic configuration of copper can be written as,
Cu (29)− [Ar] $3d^{ 10 }4s^{ 1 }$
-In the case of CuCl, the electron is lost from the 4s orbital, which is the outermost orbital.
-Here, in ${ Cu }_{ 2 }{ Cl }_{ 2 }$ or indeed CuCl the oxidation state of Cu is +1, which makes the valency equal to 1.
-Since each of the ${ Cl }^{ - }$ ions has a -1 charge and the stoichiometry is 1:1.
Hence, we can say that the valency of Cu in cuprous chloride (${ Cu }_{ 2 }{ Cl }_{ 2 }$) is 1.

Therefore, we can conclude that the correct answer to this question is option A.

Note:
Copper being a transition metal exhibits variable valencies of 1 and 2. Copper forms two types of chlorides - cuprous chloride, ${ Cu }_{ 2 }{ Cl }_{ 2 }$, and cupric chloride, $CuCl_{ 2 }$.