Calculate the mass of hydrogen required for hydrogenation of 56 grams of ethylene.

By the condition of the problem, we compose the equation
С2Н4 + Н2 = С2Н6 – hydrogenation reaction in the process of which hydrogen is added due to the breaking of a double bond, ethane is obtained;
Let’s make calculations using the formulas:
M (C2H4) = 28 g / mol;
M (H2) = 2 g / mol.
Let us determine the number of moles of ethylene, if the mass is known:
Y (C2H4) = m / M = 56/28 = 2 mol;
According to the equation, the number of moles of ethylene, hydrogen and ethane are equal to 1 mole, which means that Y (H2) = 2 moles.
Let’s calculate the mass of hydrogen:
m (H2) = Y * M = 2 * 2 = 4 g.