Question: A tablet of Vitamin C is analyzed for its ascorbic acid content. One tablet reacts exactly with 20 m...

Question

A tablet of Vitamin C is analyzed for its ascorbic acid content. One tablet reacts exactly with 20 ml of 0.1 Normal NaOH Solution. The equivalent weight of Ascorbic acid is 176. The tablet Contains $\\_\\_\\_\\_\\_\\_\\_mg$ of ascorbic Acid
A. 0.352
B. 3.52
C. 35.2
D. 352

Answer 1

Solution

For any reaction, we can equate the number of equivalences for reactants and products. By using a number of equivalences of a substance ${{n}_{eq}}$ , we calculate the values and substitute and find out the weight of the ascorbic acid in milligrams.

Complete step by step answer:
For any reaction, we can equate the number of equivalences for reactants and products. Let us calculate the number of equivalences of a substance by using the formula ${{n}_{eq}}=n.{{n}_{f}}=N.V$ .
Where in the given equation, n indicated number of moles of the given substance
${{n}_{f}}$ is the n-factor ( which is nothing but the value obtained after dividing molar weight ( represented as capital m ( M ) ) by Equivalent weight( represented as capital e ( E ) ) of the given substance )
N is normality of the given substance and V is volume of the given substance in liters.
Now let us find the ${{n}_{eq}}$ of the ascorbic acid
${{n}_{eq}}$ of the ascorbic acid $=n.{{n}_{f}}=n.\dfrac{M}{V}=n.\dfrac{176}{176}=n$
Now let us find out the ${{n}_{eq}}$ of $NaOH$
${{n}_{eq}}$ of $NaOH$$$$=N.V=(0.1)\left( \dfrac{20}{1000} \right)=0.002$
Now let us equate but the values we get are the number of moles of ascorbic acid as 0.002.
$\Rightarrow n=0.002$ moles of ascorbic acid.
Now let us calculate the weight of ascorbic acid by multiplying the number of moles with molar weight we get
Weight of ascorbic acid $=n.M=0.002\times 176=0.352$
So we got a weight of ascorbic acid equal to 0.352 grams.
Let us convert it into milligrams, we get
Weight of ascorbic acid $=352mg$
$\therefore$ Option D is correct.

Note:
Vitamin C is a vitamin found in various foods and sold as a dietary supplement. It is used to prevent and treat scurvy. Vitamin C is an essential nutrient involved in the repair of tissue and the enzymatic production of certain neurotransmitters.