Question

The color of hydrated crystal of copper sulphate is:
A. White
B. Blue
C. Black
D. Green

Answer 1

Hint: The color to the chemical compounds is because of the presence of the chromophoric groups in the given molecules. Chromophoric functional groups absorb light and impart the color to the chemical compound.

Complete step-by-step answer: - In the question it is given that to find the color of the hydrated crystal copper sulphate is.
- Generally copper sulphate compounds or chemicals are colorless or white in nature.
- Due to the absorbance of water molecules few chemicals will get color.
- Due to the absorption of water molecules by the copper sulphate the copper sulphate will become a blue color solution.
- The absorbance and releasing of the water by copper sulphate is going to write in the form of chemical reaction and it is as follows.
\[\underset{Blue\text{ }color}{\mathop{CuS{{O}_{4}}.5{{H}_{2}}O}}\,\xrightarrow{Heat}\underset{White\text{ }color}{\mathop{\text{CuS}{{\text{O}}_{\text{4}}}}}\,+5{{H}_{2}}O\]
- By observing the above chemical reaction we can say easily that hydrated copper sulphate is blue in nature and after dehydration copper sulphate will lose its color and gain white color in nature.
- This is going to occur because at the time of crystallization of the copper sulphate we have to remove the water from copper sulphate.
- Therefore the blue color of the chemical copper sulphate is going to convert into white color copper sulphate on heating.

Note: At the time of heating the water molecules which are attached to the copper sulphate pentahydrate is going to lose the water in the form of vapor and converts blue color chemical into white color chemical.