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Question
What do you observe when caustic soda solution is added to the following solution: first a little and then in excess:
CuSO4
Write a balanced equation for this reaction.
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Solution
\[\ce{\underset{\text{Blue}}{CuSO4} + \underset{\text{colourless}}{2NaOH} -> \underset{\text{Pale blue ppt.}}{Cu(OH)2↓} + \underset{\text{colourless}}{Na2SO4}}\]
In excess of alkali, pale blue precipitate of Cu(OH)2 is insoluble.
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