Question

Calculate and record the expected mass of benzoic acid required to react with 20.00 ml of a 0.100 m sodium hydroxide solution. record the mass of benzoic acid using three significant digits in your lab notes.

Answer 1

Benzoic acid reacts with sodium hydroxide based on the equation shown in the attached picture.

It is clear that the ration between the benzoic acid and the sodium hydroxide is 1:1 in this reaction.

So, to answer this question, we will calculate the number of moles of sodium hydroxide used, equate it to the number of moles of benzoic acid and then calculate the mass of the calculated number of moles.

molarity = number of moles of solute / liter of solvent
0.1 = number of moles of sodium hydroxide / 0.02 liters
number of moles of sodium hydroxide = 0.002 moles

Therefore, number of moles of benzoic acid is also 0.002 moles
molar mass of benzoic acid = 122.12 grams

Therefore, the required mass of benzoic acid = 0.002 x 122.12
                                                                         = 0.2444 moles