Question

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. 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, endothermic –9 kJ/mol, endothermic 9 kJ/mol, endothermic 9 kJ/mol, endothermic –9 kJ/mol, exothermic

Answer 1

To determine the total energy change of the reaction and classify it as endothermic or exothermic, we need to calculate the difference between the energy of the products and the energy of the reactants.

Given:

• Energy of reactants (H2 + I2) = 581 kJ/mol
• Energy of products (2HI) = 590 kJ/mol

The energy change (ΔE) can be calculated as follows:

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

Since the energy of the products is higher than the energy of the reactants, the reaction absorbs energy from the surroundings. Therefore, this is an endothermic reaction.

Thus, the correct answer is 9 kJ/mol, endothermic.