10 L of a mixture of ethylene and nitrogen was passed through a dish with bromine water, while the mass

10 L of a mixture of ethylene and nitrogen was passed through a dish with bromine water, while the mass of the glass increased by 2.8 g. Determine the volume fraction (in%) of ethibene in the mixture. Mr (C2H4) = 28.

Given:
V mixture (C2H4, N2) = 10 l
Δm = 2.8 g

To find:
φ (C2H4) -?

Solution:
1) Write the reaction equation:
C2H4 + Br2 => C2H4Br2;
2) Determine the mass of C2H4:
m (C2H4) = Δm = 2.8 g;
3) Calculate the amount of substance C2H4:
n (C2H4) = m (C2H4) / M (C2H4) = 2.8 / 28 = 0.1 mol;
4) Calculate the volume of C2H4:
V (C2H4) = n (C2H4) * Vm = 0.1 * 22.4 = 2.24 L;
5) Calculate the volume fraction of C2H4:
φ (C2H4) = V (C2H4) * 100% / V mixture (C2H4, N2) = 2.24 * 100% / 10 = 22.4%.

Answer: The volume fraction of C2H4 is 22.4%.