On heating solid copper sulphate, the blue colour crystals changes into A green. B black. C white. D red. Answer and explain.?

Question

Answer

Copper Sulphate, the Blue colour crystals which seems to be dry contain water of crystallisation. When we heat the crystals, this water is removed and then salt turns white.

If you moisten the crystals again with water, you will find that Blue colour of crystals reappears.

Note:- Water of Crystallisation is the fixed number of water molecules present in one formula unit of salt.
Ex:- CuSO4.5H2O

Answer

Copper sulphate is a hydrated salt. When it is heated strongly, it changes it's colour from blue to white due to the formation of anhydrous copper sulphate.

The blue colour can be restored on adding a few drops of water.

Answer

Heating solid copper sulphate

When solid copper sulphate (CuSO4) is heated, it undergoes a chemical change. The blue color of the crystals changes into a different color. Let's explore the possible color changes and their explanations:

A. Green
When copper sulphate is heated, it can undergo a decomposition reaction. This reaction leads to the formation of copper oxide (CuO) and the release of sulphur dioxide (SO2) gas. The color of copper oxide is green, so if the crystals turn green, it indicates the formation of copper oxide.

B. Black
Another possible color change is from blue to black. This indicates the formation of anhydrous copper sulphate (CuSO4). Anhydrous copper sulphate is the dehydrated form of the compound, which means that it has lost its water molecules. The crystals turn black because the water molecules responsible for the blue color are no longer present.

C. White
If the crystals turn white upon heating, it indicates the formation of copper sulphate pentahydrate (CuSO4·5H2O). This is the hydrated form of copper sulphate, which means it contains water molecules. The white color is due to the presence of water molecules in the crystal lattice.

D. Red
The color change to red is not observed when solid copper sulphate is heated. Therefore, option D is not the correct answer in this case.

Conclusion
Upon heating solid copper sulphate, the blue color crystals can change into green, black, or white, depending on the specific reaction occurring. The color change is a result of the chemical changes happening to the compound, such as the formation of copper oxide or the loss or gain of water molecules.

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