Complete the sentence.
The colour change when water is added to anhydrous copper sulfate is white to ______.
How to approach this question
The question describes a reversible reaction. The forward reaction (heating hydrated copper sulfate) goes from blue to white. The reverse reaction is adding water to anhydrous copper sulfate. Determine the colour change for this reverse process.
Full Answer
blue
The reaction is reversible, as shown by the symbol ⇌. The forward reaction is: hydrated copper sulfate (blue) → anhydrous copper sulfate (white) + water. The reverse reaction is adding water to anhydrous copper sulfate. Therefore, the colour change will be the reverse of the forward reaction, from white back to blue.
Common mistakes
✗ Stating the colour change for the forward reaction (blue to white) instead of the reverse reaction.
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