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, endothermic
9 kJ/mol, endothermic

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

–9 kJ/mol, exothermic

Answer 1

To determine the total energy of the reaction and whether it is endothermic or exothermic, you can use the following formula:

\[ \text{ΔE} = \text{Energy of products} - \text{Energy of reactants} \]

In this case:

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

Now, substituting in the values:

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

Since the energy of the products is greater than the energy of the reactants, the reaction absorbs energy from its surroundings. Therefore, it is an endothermic reaction.

So, the correct response is:

9 kJ/mol, endothermic