Question

Hydrogenation reactions, in which H2 and an "unsaturated" organic compound combine, are used in the food, fuel, and polymer industries. In the simplest case, ethene (C2H4) and H2 form ethane (C2H6).

(a) If 138 kJ is given off per mole of C2H4 reacting, how much heat (in kJ) is released when 15.9 kg of C2H6 forms? Enter a positive number since released implies a negative number. Enter to 0 decimal places.

Answer 1

73140 kJ.

Step-by-step explanation:

Equation of the hydrogenation reaction:

C2H4 + H2 --> C2H6

Molar mass = (2*12) + (6*1)

= 30 g/mol

Mass of C2H4 = 15.9 kg

= 15900 g

Number of moles = mass/molar mass

= 15900/30

= 530 mol of C2H6

By stoichiometry, 1 mole of C2H4 is hydrogenated to give 1 mole of C2H6

Number of moles of C2H4 = 530 mole

Q = n * q

= 530 * 138 kJ

= 73140 kJ.