Question

Citric acid (C6H8O7) is a triprotic acid (It has 3 protons that can dissociate when dissolved) found naturally in lemon juice, and it is widely used as a flavoring in beverages. What is the molarity of C6H8O7 in commercially available lemon juice if 14.26 mL of 1.751 M NaOH is required in a titration to neutralize 20.00 mL of the juice

Answer 1

Answer: The molarity of citric acid that is commercially available lemon juice is 0.416 M

Explanation:

To calculate the concentration of acid, we use the equation given by neutralization reaction:

$n_1M_1V_1=n_2M_2V_2$

where,

$n_1,M_1\text{ and }V_1$ are the n-factor, molarity and volume of acid which is $C_6H_8O_7$

$n_2,M_2\text{ and }V_2$ are the n-factor, molarity and volume of base which is NaOH.

We are given:

$n_1=3\\M_1=?M\\V_1=20.00mL\\n_2=1\\M_2=1.751M\\V_2=14.26mL$

Putting values in above equation, we get:

$3\times M_1\times 20.00=1\times 1.751\times 14.26\\\\M_1=\frac{1\times 1.751\times 14.26}{3\times 20.00}=0.416M$

Hence, the molarity of citric acid that is commercially available lemon juice is 0.416 M