89.6 liters of a mixture of nitrogen and hydrogen were passed through the catalyst. After that, the mixture

89.6 liters of a mixture of nitrogen and hydrogen were passed through the catalyst. After that, the mixture took up a volume of 67.2 liters. The obtained ammonia was dissolved in 100.88 ml of a solution with a mass fraction of ammonia 12% (ρ = 0.95 g / ml). Determine the mass fraction (%) of ammonia in the resulting solution.

Given:
V mixture1 (N2, H2) = 89.6 l
V mixture2 = 67.2 l
V1 solution (NH3) = 100.88 ml
ω1 (NH3) = 12%
ρ1 solution (NH3) = 0.95 g / ml

Find:
ω2 (NH3) -?

Solution:
1) N2 + 3H2 => 2NH3;
2) V (NH3) = V mixture1 (N2, H2) – V mixture2 = 89.6 – 67.2 = 22.4 liters;
3) n (NH3) = V (NH3) / Vm = 22.4 / 22.4 = 1 mol;
4) m (NH3) = n (NH3) * M (NH3) = 1 * 17 = 17 g;
5) m1 solution (NH3) = ρ1 solution (NH3) * V1 solution (NH3) = 0.95 * 100.88 = 95.836 g;
6) m1 (NH3) = ω1 (NH3) * m1 solution (NH3) / 100% = 12% * 95.836 / 100% = 11.5 g;
7) m2 (NH3) = m (NH3) + m1 (NH3) = 17 + 11.5 = 28.5 g;
8) m2 solution (NH3) = m (NH3) + m1 solution (NH3) = 17 + 95.836 = 112.836 g;
9) ω2 (NH3) = m2 (NH3) * 100% / m2 solution (NH3) = 28.5 * 100% / 112.836 = 25.26%.

Answer: The mass fraction of NH3 is 25.26%.