Why we don't use CuSO4 directly for detection of aldehyde,why we use Cu tartrates Complex???

1 Answer
Jul 18, 2018

I am guessing at your question....

Explanation:

But we take an aldehyde and its daughter carboxylic acid...and we can assign oxidation numbers...

#Rstackrel(+I)C(=O)HrarrRstackrel(+III)C(=O)OH+2e^(-)#

And in the laboratory this is exploited as a spot test to differentiate between aldehydes and ketones...

With an aldehyde....blue #Cu^(2+)# ion is REDUCED to #Cu_2O(s)#..

#RCHO + 2Cu^(2+) + 5HO^(-) rarr underbrace(RCOO^(-) + Cu_2O(s)darr + 3 H_2O)_"colourless"#

I think the tartrate ion is there to stabilize the cupric ion. Look up Fehling's solution.