In 735 ml of 20% sulfuric acid solution, 30 ml of ammonia was added. Calculate the mass of the salt obtained if the yield is 85%.

Given:
m solution (H2SO4) = 735 mg = 0.735 g
ω (H2SO4) = 20%
V (NH3) = 30 ml = 0.03 l
η (salt) = 85%

To find:
m pract. (salt) -?

1) m (H2SO4) = ω * m solution / 100% = 20% * 0.735 / 100% = 0.147 g;
2) n (H2SO4) = m / M = 0.147 / 98 = 0.0015 mol;
3) n (NH3) = V / Vm = 0.03 / 22.4 = 0.0013 mol;
4) H2SO4 + NH3 => NH4HSO4;
5) n theory. (NH4HSO4) = n (NH3) = 0.0013 mol;
6) n practical (NH4HSO4) = η * n theory. / 100% = 85% * 0.0013 / 100% = 0.0011 mol;
7) m (NH4HSO4) = n * M = 0.0011 * 115 = 0.127 g.

Answer: The practical mass of NH4HSO4 is 0.127 g.