Question

estimate the enthalpy change for the reaction $c_{2}h_{4}(g)+h_{2}(g)\to c_{2}h_{6}(g)$ given the following bond energies.

bond	h-h	c-h	c-c	c=c

-119 kj
-392 kj
+392 kj
+119 kj
+152 kj

Explanation:

Step1: Analyze bonds broken

For \(C_2H_4\), there is \(1\) \(C = C\) bond and \(4\) \(C - H\) bonds. For \(H_2\), there is \(1\) \(H - H\) bond.
Total energy for bonds broken:

$$
LATEXBLOCK0
$$

Step2: Analyze bonds formed

For \(C_2H_6\), there is \(1\) \(C - C\) bond and \(6\) \(C - H\) bonds.
Total energy for bonds formed:

$$
LATEXBLOCK1
$$

Step3: Calculate enthalpy change

Enthalpy change \(\Delta H=\) (Energy of bonds broken) - (Energy of bonds formed)

$$
LATEXBLOCK2
$$

Answer:

-119 kJ