Question

Calculate the energy change for the reaction of H2 with I2 to give HI.

∆Hf°(HI) = 26.5

Answer 1

Answer: 53 kJ/mol

Step-by-step explanation:

Hello, for the chemical reaction you're asking, consider that its balance result:

`H_2+I_2-->2HI`

Now, the energy change is given by the difference in the standard enthalpy of formations times the stoichiometric coefficient in the chemical reaction:

`H_(rxn)^0=H_(f,HI)^0*2-H_(f,H_2)^0-H_(f,I_2)^0`

Since hydrogen and iodine are gases, their enthalpy of formation is 0 and the hydrogen iodide has a value of 26.5 kJ/moL, thus, the energy change at standard conditions is given by:

`H_(rxn)^0=26.5 kJ/mol*2\\H_(rxn)^0=53 kJ/mol`

Best regards.