Question

if 0.2879g of unknown acid in water required 17.17mL of 0.0930M NaOH for neutralization, calculate the equivalent weight of the acid.

Answer 1

Volume of NaOH = 17.17 ml = 0.01717 L

Concentration of NaOH = 0.0930 M = 0.093 mol/L

Number of moles of NaOH = 0.01717 L * 0.093 mol/L = 0.0016 mole.

If unknown acid is monoprotic then moles of acid required for neutralization = 0.0016 mole

If unknown acid is diprotic then moles of acid required for neutralization = (1/2)0.0016 mole = 0.0008 mole

We can calculate molecular mass of unknown acid, divide given mass by number of moles required.

Depending on the type of acids, then we will now how many hydrogens are replacable. Equivalent weight of acid is equal to Molecular mass / number of replacable hydrogen.