A 0.2119 g sample of an acid, HA, was neutralized by 34.7 mL of 0.0500 M NaOH solution. The molecular mass of the acid is ________.

Question

Quizplus · Accepted Answer

First, we need to calculate the number of moles of NaOH used in the neutralization reaction:

moles NaOH = Molarity x Volume (in liters)
moles NaOH = 0.0500 mol/L x 0.0347 L
moles NaOH = 0.001735 mol

Since the acid and base react in a 1:1 ratio (according to the balanced chemical equation), we know that the number of moles of acid used in the reaction is also 0.001735 mol.

Next, we can use the mass and moles of the acid to calculate its molar mass:

Molar mass = Mass / Moles
Molar mass = 0.2119 g / 0.001735 mol
Molar mass = 122.17 g/mol

Therefore, the molecular mass of the acid is 122.17 g/mol, which corresponds to choice C.

A 02119 G Sample of an Acid, HA, Was Neutralized by by 34.7