Calculate the mass of soap that can be obtained from 200 g of stearic acid with a mass

Calculate the mass of soap that can be obtained from 200 g of stearic acid with a mass fraction of impurities of 15% when treated with alkali. name the resulting salt.

Given:
m tech. (C17H35COOH) = 200g
ω approx. = 15%

To find:
m (soap) -?

1) C17H35COOH + NaOH => C17H35COONa + H2O;
2) ω (C17H35COOH) = 100% – ω approx. = 100% – 15% = 85%;
3) m clean. (C17H35COOH) = ω * m tech. / 100% = 85% * 200/100% = 170 g;
4) n (C17H35COOH) = m pure. / M = 170/284 = 0.6 mol;
5) n (C17H35COONa) = n (C17H35COOH) = 0.6 mol;
6) m (C17H35COONa) = n * M = 0.6 * 306 = 184 g;
7) C17H35COONa – sodium octadecanoate (sodium stearate).

Answer: The mass of C17H35COONa is 184 g.