Question

question 5
use the equation above to help you calculate the heat of combustion of ethylene, c₂h₄. the bond energies you possibly need are: c - h 416 kj/mol; c - c 356 kj/mol; c = c 598 kj/mol; o = o 498 kj/mol; c = o 803 kj/mol; h - o 467 kj/mol.
the heat of combustion of ethylene is? show your work. work copied from internet sources or ai tools will receive a score of 0.

Explanation:

Step1: Determine bonds broken in reactants

In $C_2H_4$, there are 4 C - H bonds and 1 C = C bond. In 3 $O_2$, there are 3 O = O bonds.
$E_{broken}=(4\times416 + 598+3\times498)$ kJ/mol
$E_{broken}=(1664 + 598+1494)$ kJ/mol
$E_{broken}=3756$ kJ/mol

Step2: Determine bonds formed in products

In 2 $CO_2$, there are 4 C = O bonds. In 2 $H_2O$, there are 4 H - O bonds.
$E_{formed}=(4\times803+4\times467)$ kJ/mol
$E_{formed}=(3212 + 1868)$ kJ/mol
$E_{formed}=5080$ kJ/mol

Step3: Calculate heat of combustion

$\Delta H=E_{broken}-E_{formed}$
$\Delta H = 3756 - 5080=-1324$ kJ/mol

Answer:

• 1324 kJ/mol