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W14 Lemon juice contains two different acids

Lemon juice tastes sour because it contains citric acid and a second one called  ascorbic acid (= vitamin C).
* Left: The upper left blister contains pure vitamin C, citric acid is in the the right  one. Below each acid a numulite was placed in each of the acid solutions.
* Observations: The two acids solutions react with the acid solutio numulites like in the previous experiment releasing gas bubbles.
* Right: The two numulites have disappeared, they are corroded by citric acid and ascorbic acid. Two new substances have been formed: The gas and a new solid which is dissolved.