Chlorination of ethylene yields 15 g of dichloroethane. The reaction is … ethylene.

Let’s execute the solution:
1. In accordance with the condition of the problem, we write the equation:
X g -? m = 15 g.
С2Н4 + Сl2 = C2H4Cl2 – addition, dichloroethane was obtained;
1 mol 1 mol.
2. Calculation of the molar masses of substances:
M (C2H4) = 28 g / mol;
M (C2H4Cl2) = 99 g / mol.
3. Determine the amount of dichloroethane, if the mass is known:
Y (C2H4Cl2) = m / M = 15/99 = 0.15 mol;
Y (C2H4) = 0.15 mol since the amount of substances according to the equation is 1 mol.
4. Find the mass of the original substance:
m (C2H4) = Y * M = 0.15 * 28 = 4.2 g.
Answer: ethylene weighing 4.2 g is required to carry out the process.