Question

3. Suppose you wish to extract 10 g of benzoic acid from an ether solution with aqueous NaHCO3. (a) Write the equation for the reaction of benzoic acid and NaHCO3 (b) What is the minimum amount of NaHCO3 that must be added to 50 mL of water to carry out the extraction?

Answer 1

Answer:

The minimum amount is 6,9 g

Explanation:

The extraction of benzoic acid with aqueous NaHCO₃ is an Acid-Base Reaction, where the benzoic acid loses a proton to the sodium bicarbonate, as follows:

(a)  Ф-COOH + NaHCO₃   ↔ Ф-COO⁻ + NaH₂CO₃⁺

In order to calculate the amount of bicarbonate needed, some conversion factors need to be used:

10 g acid *  $\frac{1 mol acid}{122 g} * \frac{1 mol bicarbonate}{1 mol acid} * \frac{84g}{1 mol bicarbonate} = 6,9 g$

Thus, 6,9 g of sodium bicarbonate would need to be added in order to extract 10 g of benzoic acid