29 Caffeine, a stimulant in tea Appliquer ses connaissances - Réaliser des calculs The infusion of tea leaves contains some caffeine. This chemical species acts on the nervous system. It is a stimulant. After infusing of 15 g of leaves, we extract 0.75 g of caffeine.
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Mass percentage of caffeine in coffee: the highest is 2.5 % for the Robusta coffee, the richest in caffeine.
1. a. Calculate the mass percentage of caffeine in tea leaves.
b. Which drink, tea or coffee, stimulates the nervous system the most? Justify. 2. We perform a CCM of the tea. We notice several spots.
a. Why is it necessary to examine the chromatogram under an ultraviolet lamp? b. Justify that tea is a mixture.
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