How much ethylene can be obtained from 200 ml of ethyl alcohol? Density (C2H5OH) = 0.821 ml.

Find the mass of the alcohol solution C2H5OH.
m = Vp
m = 200 ml × 0.821 g / ml = 164.2 g.
Let us find the amount of alcohol substance C2H5OH.
M (C2H5OH) = 46 g / mol.
n = 164.2 g: 46 g / mol = 3.57 mol.
Let’s compose the reaction equation, find in what quantitative ratios the substances are.
С2Н5ОН → С2Н4 + Н2О
According to the reaction equation, there is 1 mol of C2H4 for 1 mol of С2Н5ОН. Substances are in quantitative ratios 1: 1.
n (C2H5OH) = n (C2H4) = 3.57 mol.
Let’s find the volume of C2H4.
V = n Vn, where Vn is the molar volume of the gas equal to 22.4 l / mol.
V = 3.57 mol × 22.4 L / mol = 79.97 L.
Answer: 79.97 liters.