If 27.50 mL of 0.120 M NaOH neutralizes 0.248 g of HAA, what is the molar mass of unknown amino acid

75.15 g/mol

Explanation:

First, let us look at the equation of reaction;

From the balanced equation of reaction, 1 mole of NaOH is required to completely neutralize 1 mole of HAA.

Recall that: mole = molarity x volume.

Therefore, 27.50 mL, 0.120 M NaOH = 0.0275 x 0.120 = 0.0033 moles

0.0033 mole of NaOH will therefore requires 0.0033 moles of HAA for complete neutralization.

In order to find the molar mass of the unknown amino acid, recall that:

mole = mass/molar mass, hence, molar mass = mass/mole.

Therefore, molar mass of HAA = 0.248/0.0033 = 75.15 g/mol