The value of ΔH° for the reaction below is -72 kJ. ________ kJ of heat are released when 80.9 grams of HBr is formed in this reaction. H₂ (g) + Br₂ (g) → 2HBr (g) A)144 B)72 C)0.44 D)36 E)-72

Question

Quizplus · Accepted Answer

To solve for the amount of heat released during the formation of 80.9 grams of HBr, we first need to calculate the moles of HBr formed in the reaction:

2 moles of HBr are formed for every 1 mole of HSBr and Br2 that react, so for every 2 moles of HBr formed, ΔH° is -72 kJ.
Thus, to calculate the amount of heat released for 1 mole of HBr formed, we do:

-72 kJ / 2 mol HBr = -36 kJ/mol HBr

Now we can convert the grams of HBr to moles using the molar mass of HBr (80.9 g / 80.91 g/mol = 1 mol HBr) and multiply by the amount of heat released per mole:

1 mol HBr x -36 kJ/mol HBr = -36 kJ

Therefore, the amount of heat released when 80.9 grams of HBr is formed in the reaction is 36 kJ.

The correct answer is D (36).

The Value of ΔH° for the Reaction Below Is -72