Question

(a)- Write formula of sodium dicyanoaurate (I) complex
(b)- Define anisotropy

Answer 1

Hint: The name sodium dicyanoaurate (I) complex suggests that it is a coordination complex in which cation and anion are present. The sodium will be the cation and the dicyanoaurate (I) complex will be the anion. Aurate is used for the gold metal. Anisotropy is the property of crystalline solids which makes them different from amorphous solids.

Complete Solution :
(a)- The name sodium dicyanoaurate (I) complex suggests that it is a coordination complex in which cation and anion are present. In the name of the complex sodium dicyanoaurate (I) complex, sodium is written first so it will be the cation, and dicyanoaurate (I) complex will be the anion. Dicyano means there are two molecules of $CN$ and the term ‘Aurate' is used for the gold metal. The oxidation number of gold is +1, and the oxidation state of the cyano group is -1, therefore there must be one sodium atom in the complex.
So, the formula will be: $Na[Au{{(CN)}_{2}}]$

(b)- Anisotropy is the property of crystalline solids which makes them different from amorphous solids. Anisotropy is the property or behavior in which properties like electrical conductivity, refractive index, thermal expansion, etc, will have different values in a different direction. This behavior is only shown by crystalline solids because they have regular geometry. And we can call all crystalline solids as anisotropic.
So, the correct answer is “Option B”.

Note: The crystalline solids show anisotropic behavior whereas amorphous solids show isotropic behavior in which the properties like electrical conductivity, refractive index, thermal expansion, etc will have the same values in the different direction.