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 ($\mathrm{\Delta }E$) is:

$$\mathrm{\Delta }E=E_{\text{products}}-E_{\text{reactants}}$$

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:

$$\mathrm{\Delta }E=590,\text{kJ/mol}-581,\text{kJ/mol}=9,\text{kJ/mol}$$

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

So the correct response is:

9 kJ/mol, endothermic