When producing hydrogen iodide, the energy of the reactants is 581 kJ/mol, and the energy of the products is 590 kJ/mol. The equation is shown.

Question

H2 + I2 → 2HI

What is the total energy of the reaction? Is this an endothermic or exothermic reaction?

(1 point)
Responses

–9 kJ/mol, exothermic
–9 kJ/mol, exothermic

9 kJ/mol, exothermic
9 kJ/mol, exothermic

9 kJ/mol, endothermic
9 kJ/mol, endothermic

–9 kJ/mol, endothermic

Answer 1

To determine the total energy change of the reaction, we need to calculate the difference in energy between the products and the reactants. The formula for the change in energy (\( \Delta E \)) is:

\[ \Delta E = E_{\text{products}} - E_{\text{reactants}} \]

Given:

• Energy of reactants (\( E_{\text{reactants}} \)) = 581 kJ/mol
• Energy of products (\( E_{\text{products}} \)) = 590 kJ/mol

Now, we can plug in the values:

\[ \Delta E = 590 , \text{kJ/mol} - 581 , \text{kJ/mol} = 9 , \text{kJ/mol} \]

Since the energy change is positive (\( \Delta E = 9 , \text{kJ/mol} \)), this indicates that energy is absorbed during the reaction. Therefore, the reaction is endothermic.

So the correct response is:

9 kJ/mol, endothermic