Question

swyk: energy & chemical reactions
3 of 4
possible points 6
fill the the blank with the appropriate answer based on the energy diagram below.
the energy of the reactants is (in kj) and the energy of the products is (in kj). this means that the heat of reaction or △h is (in kj). because of the heat in reaction that means that this reaction is
the energy of the transition state/or activated complex (in kj) is. this means the activation energy (in kj) for this reaction shown below is
pe (kj)
100
80
60
40
20
a + b
c + d
progress of the reaction
endothermic exothermic -20 20 40 60 100

Explanation:

Step1: Identify reactant energy

From the graph, the energy of reactants \(A + B\) is at \(40\) kJ.

Step2: Identify product energy

The energy of products \(C + D\) is at \(20\) kJ.

Step3: Calculate heat of reaction

The heat of reaction \(\Delta H=E_{products}-E_{reactants}\), so \(\Delta H = 20 - 40=- 20\) kJ.

Step4: Determine reaction type

Since \(\Delta H<0\), the reaction is exothermic.

Step5: Identify transition - state energy

The energy of the transition state (the peak of the curve) is \(100\) kJ.

Step6: Calculate activation energy

Activation energy \(E_a\) is the energy difference between the transition - state and the reactants. So \(E_a=100 - 40 = 60\) kJ.

Answer:

The energy of the reactants is \(40\) (in kJ) and the energy of the products is \(20\) (in kJ). This means that the heat of reaction or \(\Delta H\) is \(-20\) (in kJ). Because of the heat in reaction that means that this reaction is Exothermic. The energy of the transition state/ or activated complex (in kJ) is \(100\). This means the activation energy (in kJ) for this reaction shown below is \(60\).