Carboxylic acid in the end can not react with the new copper hydroxide
But the formula is written in the carboxylic acid, because the reaction of aldehydes with the new copper hydroxide is alkaline conditions, the carboxylic acid is not present, but the carboxylic acid and alkali, copper hydroxide, copper oxide are reaction, Side reactions too much, too complex, in order to show that the reaction principle, simply from the simple processing, directly write carboxylic acid
