Questions & Answers

The acid present in tea is:
A. tannic
B. lactic
C. tartaric
D. citric

Answer Verified Verified
Hint: There are a variety of acidic and basic compounds present in tea naturally. Overall, the pH of tea is mildly acidic. Acidity also depends upon the type of the tea and how long it is brewed.

Complete step by step solution:

First, let's know how tea is made.
Tea is processed from the young leaves and buds of the tea plant. It contains numerous substances which help to relieve tension and provide refreshment and the amounts of these substances vary in different types of tea leaves, which makes their tastes and flavors different.

Tannins are one of these naturally occurring substances. Tannic acid is a specific form derived from tannin. It is a type of polyphenol. Due to the presence of numerous phenol groups in the structure the acidity weakens (pH around 10). The chemical structure of tannic acid is given below.

The chemical formula of tannic acid used for commercial purposes is often given as \[{{C}_{76}}{{H}_{52}}{{O}_{46}}\]. It has a molar mass of 1,701.19 g/ mol and solubility in water is 2.85 g/$cm^3$.
The level of tannic acid present in 5g of the most popular brands of teas are:

Tea brandPercentage of tannic acid
TATA Tea14.9
Lipton Green Tea2.65
Red Label Tea12.4

So, the correct option is (a).

Note: Tea leaves contain many compounds such as polyphenols, amino acids, enzymes, pigments, carbohydrates, methylxanthines, etc. Tannins present in tea are very good antioxidants which may help in fighting cavities, and diarrhea.
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