Under the action of bromine water on 10 g of aniline solution in benzene, a precipitate weighing 1.1

Under the action of bromine water on 10 g of aniline solution in benzene, a precipitate weighing 1.1 g was formed. determine the mass fraction of benzene in the original solution

Given:
m solution = 10 g
m (sediment) = 1.1 g

To find:
ω (C6H6) -?

1) 3Br2 + C6H5NH2 => C6H2Br3NH2 ↓ + 3HBr;
2) M (C6H2Br3NH2) = 330 g / mol;
3) n (C6H2Br3NH2) = m (C6H2Br3NH2) / M (C6H2Br3NH2) = 1.1 / 330 = 0.003 mol;
4) n (C6H5NH2) = n (C6H2Br3NH2) = 0.003 mol;
5) M (C6H5NH2) = 93 g / mol;
6) m (C6H5NH2) = n (C6H5NH2) * M (C6H5NH2) = 0.003 * 93 = 0.279 g;
7) m (C6H6) = m solution – m (C6H5NH2) = 10 – 0.279 = 9.721 g;
8) ω (C6H6) = m (C6H6) * 100% / m solution = 9.721 * 100% / 10 = 97.21%.

Answer: The mass fraction of C6H6 is 97.21%.