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, endothermic
–9 kJ/mol, endothermic

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

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

–9 kJ/mol, exothermic

Answer 1

To determine the total energy change of the reaction, we can use the formula:

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

In this case, the energy of the reactants (H2 + I2) is 581 kJ/mol, and the energy of the products (2HI) is 590 kJ/mol.

Now, calculate the change in energy:

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

Since the energy of the products is greater than that of the reactants, the reaction absorbs energy. Therefore, it is classified as an endothermic reaction.

So the correct answer is:

9 kJ/mol, endothermic.