Question

Use the picture below to answer this question. What is the total bond energy? Is the reaction exothermic or endothermic? Use the structures and bond energy to answer. C2H4 + H2 > C2H6. Refer to this list of bond energies for the molecules, Bonds Energy C (double bond) 614 kJ/mol H CH 413 kl mol H.H I-O-I HH 452 kmol H H Celona 4347 kJ/mol

Answer 1

1) Set the chemical equation.

$C_2H_4+H_2\rightarrow C_2H_6$

2) Calculating total bond energy

$\Delta H\text{ = }\Sigma H_{(\text{bonds broken)}}\text{ - }\Sigma H_{(\text{bonds fromed)}}$

3) How many bonds were broken and formed?

One double bond between Carbons was broken, and the single bond between Hydrogens was broken.

Two single bonds between Carbon and Hydrogen were formed.

4) Calculating total bond energy

$\Delta H=(\frac{614kJ}{\text{mol}}+\frac{432kJ}{\text{mol}})-(\frac{413kJ}{\text{mol}}+\frac{413kJ}{\text{mol}})$

The total bond energy in the reaction is +220kJenergy