What volume of sodium hydroxide solution with a mass fraction of 25% and a density of 1.23

What volume of sodium hydroxide solution with a mass fraction of 25% and a density of 1.23 g / ml is required for the complete hydrolysis of 15 g of propionic acid methyl ester?

Given:
m (C2H5COOCH3) = 15 g;
ω (NaOH) = 25%;
ρ (NaOH) = 1.23 (g / mol);
V solution (NaOH) -?
Decision:
Let’s write the equation of alkaline hydrolysis:
C2H5COOCH3 + NaOH solution → CaH5COONa + CH3OH.
M (C2H5COOCH3) = 12 * 4 + 1 * 8 + 2 * 16 = 88 (g / mol).
n (C2H5COOCH3) = 15/88 = 0.17045 ≈ 0.17 (mol).
n (NaOH) = n (C2H5COOCH3) = 0.17 (mol).
m (NaOH) = n * M = 0.17 * 40 = 6.8 (d).
m p – pa (NaOH) = 6.8 / 0.25 = 27.2 (g).
Find the volume of sodium hydroxide solution:
V p – pa (NaOH) = m p – pa (NaOH) / ρ (NaOH) = 27.2 / 1.23 = 22.1138 ≈22.1 (ml).
Answer: The volume of the NaOH solution is 22.1 ml.